User:Rukario-sama/sandbox

Market share overview According to StatCounter data October 2024

Browser % of Fx % of total Firefox 1 — — Firefox 2 — — Firefox 3 — — Firefox 4 — — Firefox 5–9 — — Firefox 10–16 0.38% 0.01% Firefox 17–23 — — Firefox 24–30 — — Firefox 31–37 — — Firefox 38–44 — — Firefox 45–51 — — Firefox 52–59 2.26% 0.06% Firefox 60–67 — — Firefox 68–77 — — Firefox 78–90 0.38% 0.01% Firefox 91–101 — — Firefox 102–114 — — Firefox 115 and 115 ESR 11.32% 0.30% Firefox 116 — — Firefox 117 — — Firefox 118 2.64% 0.07% Firefox 119 — — Firefox 120 — — Firefox 121 — — Firefox 122 — — Firefox 123 — — Firefox 124 — — Firefox 125 0.76% 0.02% Firefox 126 0.76% 0.02% Firefox 127 0.76% 0.02% Firefox 128 and 128 ESR 2.26% 0.06% Firefox 129 1.13% 0.03% Firefox 130 9.06% 0.24% Firefox 131 58.87% 1.56% Firefox 132 2.26% 0.06% Firefox 133 — — All variants 100% 2.65%

Mozilla Firefox was created by Dave Hyatt and Blake Ross as an experimental branch of the Mozilla browser, first released the Firefox 1.0 on November 9, 2004. Since version 5.0, a rapid release cycle was put into effect, resulting in a new major version release every six weeks on Tuesday. Firefox 66 is the latest version released on March 19, 2019.

Current and future releases

Current supported official releases

• Firefox 66.0.3
• Firefox 60.6.1 ESR

Current supported test releases

• Firefox 67.0 Beta
• Firefox 67.0 Developer Edition
• Firefox 68.0 Nightly

Future official releases

Rapid

• Firefox 67.0
• Firefox 68.0
• Firefox 69.0
• Firefox 70.0
• Firefox 71.0

ESR

• Firefox 60.7 ESR
• Firefox 60.8 ESR
• Firefox 60.9 ESR
• Firefox 68.0 ESR
• Firefox 68.1 ESR
• Firefox 68.2 ESR
• Firefox 68.3 ESR

Future test releases

• Firefox 68.0 Developer Edition
• Firefox 68.0 Beta
• Firefox 69.0 Nightly
• Firefox 69.0 Developer Edition
• Firefox 69.0 Beta
• Firefox 70.0 Nightly
• Firefox 70.0 Developer Edition
• Firefox 70.0 Beta
• Firefox 71.0 Nightly
• Firefox 71.0 Developer Edition
• Firefox 71.0 Beta
• Firefox 72.0 Nightly
• Firefox 72.0 Developer Edition
• Firefox 72.0 Beta
• Firefox 73.0 Nightly

Early versions

The project that became Firefox today began as an experimental branch of the Mozilla Suite called m/b (or mozilla/browser). Firefox retains the cross-platform nature of the original Mozilla browser, using the XUL user interface markup language. The use of XUL makes it possible to extend the browser's capabilities through the use of extensions and themes. The development and installation processes of these add-ons raised security concerns, and with the release of Firefox 0.9, the Mozilla Foundation opened a Mozilla Update website containing "approved" themes and extensions. The use of XUL sets Firefox apart from other browsers, including other projects based on Mozilla's Gecko layout engine and most other browsers, which use interfaces native to their respective platforms (Galeon and Epiphany use GTK+, K-Meleon uses MFC, and Camino uses Cocoa). Many of these projects started before Firefox, and probably served as inspiration.

Phoenix and Firebird

Phoenix 0.1, the first official release

Hyatt, Ross, Hewitt and Chanial developed their browser to combat the perceived software bloat of the Mozilla Suite (codenamed, internally referred to, and continued by the community as SeaMonkey), which integrated features such as IRC, mail, news, and WYSIWYG HTML editing into one internet suite. After it was sufficiently developed, binaries for public testing appeared in September 2002 under the name Phoenix. This name carried the implication of the mythical firebird that rose triumphantly from the ashes of its dead predecessor, in this case Netscape Navigator which lost the "First browser war" to Microsoft's Internet Explorer. The name Mozilla began as the internal codename for the original 1994 Netscape Navigator browser aiming to displace NCSA Mosaic as the world's most popular web browser. The name for this would-be "Mosaic killer" was meant to evoke the building-crushing Godzilla. The name Mozilla was revived as the 1998 open sourcing spinoff organization from Netscape.

The name Phoenix remained until April 14, 2003, when it was changed because of a trademark dispute with the BIOS manufacturer Phoenix Technologies (which produces a BIOS-based browser called Phoenix FirstWare Connect). The new name, Firebird, met with mixed reactions, particularly as the Firebird database server already carried the name. In response, the Mozilla Foundation stated that the browser should always bear the name Mozilla Firebird to avoid confusion with the database software.

Release history of Phoenix
Version	Codename	Release date	Release type and highlights
0.1	Pescadero	September 23, 2002	First release. Gecko version 1.2 Customizable toolbar Quicksearch
0.2	Santa Cruz	October 1, 2002	Official version 0.2 release. Web form auto-complete Sidebar Downloads Sidebar Bookmarks Sidebar History Sidebar Extension management Toolbar customization Search bar Improved preference defaults Speed improvements Ctrl+Mousewheel to resize fonts
0.3	Lucia	October 14, 2002	Official version 0.3 release. Image Blocking Pop-up Blocking Whitelist Bookmarks Changes Global Go Menu and Other Menu Changes Tabbed Browsing Improvements Size and Speed Improvements
0.4	Oceano	October 19, 2002	Official version 0.4 release. Gecko version 1.3 Improvements to pop-up blocking Improvements to toolbar customization Improvements to tabbed browsing and shortcut keys Type ahead find returns Address bar gets smarter Themes
0.5	Naples	December 7, 2002	Official version 0.5 release. Multiple homepages Intellimouse 5-button support Sidebar remembers its state across sessions Download fixes History improvements Accessibility improvements Size and memory reduction Performance improvements Stability improvements Better Windows appearance Many more new themes

Release history of Firebird
Version	Codename	Release date	Release type and highlights
0.6	Glendale	May 17, 2003	Official version 0.6 release. Gecko version 1.5 New default theme (Qute) Redesigned Preferences window Improved Privacy Options Improved Bookmarks Talkback enabled to tell Mozilla why the browser crashed Automatic Image Resizing Smooth Scrolling Access to more preferences through about:config Custom profile save location Mac OS X compatibility
0.6.1		July 28, 2003	Bugfix release.
0.7	Indio	October 15, 2003	Technology Preview. First publication on October 26, 2003 Advanced preferences panel Download/helper applets preferences panel Cookie whitelisting New password manager (all passwords now stored encrypted) Web panels (like Mozilla's sidebar panels) Alternate stylesheet support (through a status bar button) Send Page, Send Link, and Send Image menu items Autoscroll
0.7.1	Three Kings	October 26, 2003	Bugfix release for Mac OS X only.

Firefox

Firefox 1.0, the first release targeted for general public

Due to continuing pressure from the Firebird community, on February 9, 2004 the project was renamed again to Mozilla Firefox. The name "Firefox" (a reference to the red panda) was chosen for its similarity to "Firebird", and its uniqueness in the computing industry. To ensure that no further name changes would be necessary, the Mozilla Foundation began the process of registering Firefox as a trademark with the United States Patent and Trademark Office in December 2003. This trademark process led to a delay of several months in the release of Firefox 0.8 when the foundation discovered that Firefox had already been registered as a trademark in the UK for Charlton Company software. The situation was resolved when the foundation was given a license to use Charlton's European trademark.

Firefox version 1.0 was released on November 9, 2004. The launch of version 1.0 was accompanied by "a respectable amount of pre-launch fervor" including a fan-organized campaign to run a full-page ad in The New York Times.

Although the Mozilla Foundation had intended to make the Mozilla Suite obsolete and replace it with Firefox, the Foundation continued to maintain the suite until April 12, 2006 because it had many corporate users and was bundled with other software. The Mozilla community (as opposed to the Foundation) continues to release new versions of the suite, using the product name SeaMonkey to avoid confusion with the original Mozilla Suite.

Pre-release history of Firefox
Version	Codename	Release date	Release type and highlights
0.8	Royal Oak	February 9, 2004	Technology Preview. Gecko version 1.6 Rebranded with new logo. Windows installer Download Manager New Add Bookmark Dialog Work Offline Better Handling of File Types New XPInstall Frontend New default theme for Mac OS X.
0.9	One Tree Hill	June 15, 2004	Technology Preview. Gecko version 1.7 New default theme "Winstripe". Comprehensive Data Migration from Internet Explorer. Extension/Theme Manager Online help system Linux installer
0.9.1		June 28, 2004	Bugfix release Updated default theme
0.9.2		July 8, 2004	Vulnerability patch for Windows only.
0.9.3		August 4, 2004	Vulnerability patch.
0.10	Greenlane	September 14, 2004	Bugs with higher complexity/risk, localization impact, RSS/Atom feed support, find toolbar, plugin finder.
0.10.1		October 1, 2004	Vulnerability patch.

Release history of Firefox 1
Version	Codename	Release date	Release type and highlights
1.0	Phoenix	November 9, 2004	Official version 1.0 release. Better Tabbed Browsing Controls Official localized builds
1.0.1	Rose & Crown	February 24, 2005	Regular security and stability update.
1.0.2		March 23, 2005	Regular security and stability update.
1.0.3		April 15, 2005	Regular security and stability update. Installer improvements.
1.0.4		May 11, 2005	Regular security and stability update. Fix to DHTML errors encountered at some web sites.
1.0.5		July 12, 2005	Regular security and stability update.
1.0.6		July 19, 2005	Off-cycle stability update. Restored API compatibility for extensions and web applications that did not work in Firefox 1.0.5.
1.0.7		September 20, 2005	Regular security and stability update.
1.0.8		April 13, 2006	Regular security and stability update. End-of-life 1.0.x product line Last release for Mac OS X 10.0–10.1

Firefox 1.5

"Deer Park", the codename of the Firefox 1.1 and 1.5 Alphas, did not include Firefox branding.

Firefox 1.5 was released on November 30, 2005. Originally, it was planned to have a version 1.1 at an earlier date as the new Firefox version after 1.0, with development on a later version (1.5) in a separate development branch, but during 2005 both branches and their feature sets were merged (the Mozilla Foundation abandoned the 1.1 release plan after the first two alpha builds), resulting in an official release date between the original dates planned for both versions.

Version 1.5 implemented a new Mac-like options interface, the subject of much criticism from Microsoft Windows and Linux users, with a "Sanitize" action to allow someone to clear their privacy-related information without manually clicking the "Clear All" button. In Firefox 1.5, a user could clear all privacy-related settings simply by exiting the browser or using a keyboard shortcut, depending on their settings. Moreover, the software update system was improved (with binary patches now possible). There were also improvements in the extension management system, with a number of new developer features. In addition, Firefox 1.5 had preliminary SVG 1.1 support.

Behind the screens, the new version resynchronized the code base of the release builds (as opposed to nightly builds) with the core "trunk", which contained additional features not available in 1.0, as it branched from the trunk around the 0.9 release. As such, there was a backlog of bug fixes between 0.9 and the release of 1.0, which were made available in 1.5.

There were also changes in operating system support. As announced on 23 June 2005 by the Mozilla Foundation, Firefox 1.1, which later became 1.5, and other new Mozilla products did no longer support Mac OS X v10.1, in order to improve the quality of Firefox releases on Mac OS X v10.2 and above. Firefox 1.5.0.12 was the final version supported on Windows 95.

Alpha builds of Firefox 1.5 (id est, 1.1a1 and 1.1a2) did not carry Firefox branding; they were labelled "Deer Park" (which was Firefox 1.5's internal codename) and contained a different program icon. This was done to dissuade end-users from downloading preview versions, which are intended for developers only.

Release history of Firefox 1.5
Version	Codename	Release date	Release type and highlights
1.5	Deer Park	November 29, 2005	Official version 1.5 release. Official localized builds. Gecko version 1.8 Private data clear data Back and forward now fast Improved web standards Improved HTML Improved CSS Improved HTTP Improved JavaScript/DOM SVG compatibility Changes during alphas Support for SVG and canvas. Sanitize privacy feature. Improvements in JavaScript 1.5 and CSS 2/3. Broken website reporter tool. Blazing fast backwards and forwards (FastBack), drag-and-drop tab reordering, improved pop-up blocking, error pages instead of error dialogs. Changes during betas New update system (binary patch). Prettier error pages, more Luna-like Winstripe theme (did not blend well with the Classic theme). Improvements to automated update system, website rendering and performance. Several security fixes.
1.5.0.1		February 1, 2006	Regular security and stability update.
1.5.0.2		April 13, 2006	Regular security and stability update. Native support for Intel-based Macintosh computers by shipping universal binary.
1.5.0.3		May 2, 2006	Off-cycle security update. Fix for a publicly disclosed denial of service weakness.
1.5.0.4		June 1, 2006	Regular security and stability update.
1.5.0.5		July 26, 2006	Regular security and stability update. Added changes for Frisian locale (fy-NL).
1.5.0.6		August 2, 2006	Off-cycle security and stability update. Fixed an issue with playing Windows Media content introduced by previous update.
1.5.0.7		September 14, 2006	Regular security and stability update.
1.5.0.8		November 7, 2006	Regular security and stability update.
1.5.0.9		December 19, 2006	Regular security and stability update.
1.5.0.10		February 23, 2007	Regular security and stability update.
1.5.0.11		March 20, 2007	Regular security and stability update. Regression fixes.
1.5.0.12		May 30, 2007	Regular security and stability update. End-of-life 1.5.0.x product line Last release for Windows 95

Firefox 2

Mozilla Firefox 2.0.0.12 running on Ubuntu

Main article: Firefox 2

On October 24, 2006, Mozilla released Firefox 2. This version included updates to the tabbed browsing environment, the extensions manager, the GUI (Graphical User Interface), and the find, search and software update engines. It also implemented a new session restore feature, inline spell checking, and an anti-phishing feature which was implemented by Google as an extension and later merged into the program itself.

In December 2007, Firefox Live Chat was launched. It allowed users to ask volunteers questions through a system powered by Jive Software, with guaranteed hours of operation and the possibility of help after hours.

Firefox 2.0.0.20 was the final version that could run under an unmodified installation of Windows NT 4.0, Windows 98, and Windows ME. Subsequently, Mozilla Corporation announced it would not develop new versions of Firefox 2 after the 2.0.0.20 release, but continued Firefox 2 development as long as other programs, such as Thunderbird mail client, depended on it. The final internal release was 2.0.0.22, released in late April 2009.

Release history of Firefox 2
Version	Codename	Release date	Release type and highlights
2.0	Bon Echo	October 24, 2006	Official version 2.0 release. Official localized builds. Gecko version 1.8.1 Visual Refresh of main theme Built-in phishing protection Enhanced search capabilities Improved tabbed browsing Resuming your browsing session (session restore) Previewing and subscribing to Web feeds Inline spell checking Live Web Titles Improved Add-ons manager JavaScript 1.7 Extended search plugin format (predictive search) Improved security with extension system Client-side session and persistent storage SVG text support New Windows installer Changes during alphas" Links default to open in new tab. Close button on every tab. Inline spell checking for text boxes. Session restoration after browser crash. Search suggestion for Google and Yahoo!. New search plugin manager and add-on manager. Web feed previewing. Bookmark microsummaries. Updates to extension system. Support for Sherlock and OpenSearch. Support for SVG text using svg:textPath. Anti-phishing protection. Search suggestions appear with search history in the search box for Google and Yahoo!. Support for client-side session and persistent storage. Changes during betas Improved feed support. New NSIS-based installer. JavaScript 1.7. Enhanced security and localization support for extensions. New Winstripe theme refresh: new navigation icons, URL bar refresh (new Go button attached to the URL bar), Search bar refresh, Tab bar refresh, Alltabs button (used to view a popup list of all tabs open).
2.0.0.1		December 19, 2006	Regular security and stability update. Windows Vista support.
2.0.0.2		February 23, 2007	Regular security and stability update.
2.0.0.3		March 20, 2007	Regular security and stability update. Regression fixes and security fixes.
2.0.0.4		May 30, 2007	Regular security and stability update.
2.0.0.5		July 17, 2007	Security and stability update.
2.0.0.6		July 30, 2007	Regular security and stability update.
2.0.0.7		September 18, 2007	Off-cycle security update.
2.0.0.8		October 18, 2007	Regular security and stability update. Mac OS X 10.5 support.
2.0.0.9		November 1, 2007	Off-cycle security and stability update.
2.0.0.10		November 26, 2007	Off-cycle security and stability update.
2.0.0.11		November 30, 2007	Off-cycle stability update.
2.0.0.12		February 7, 2008	Regular security and stability update.
2.0.0.13		March 25, 2008	Regular security and stability update.
2.0.0.14		April 16, 2008	Off-cycle stability update.
2.0.0.15		July 1, 2008	Regular security and stability update.
2.0.0.16		July 15, 2008	Off-cycle security update.
2.0.0.17		September 23, 2008	Regular security and stability update.
2.0.0.18		November 12, 2008	Regular security and stability update.
2.0.0.19		December 16, 2008	Regular security and stability update.
2.0.0.20		December 18, 2008	Off-cycle security update. Last release for Windows NT 4.0, Windows 9x, Mac OS X 10.2–10.3 Bug fixes Fixed security and stability issues. End-of-life 2.0.0.x product line

Firefox 3

Mozilla Firefox 3.0 on Ubuntu

Main article: Firefox 3

Firefox 3 was released on June 17, 2008, by the Mozilla Corporation. Firefox 3 uses version 1.9 of the Mozilla Gecko layout engine for displaying web pages. This version fixes many bugs, improves standard compliance, and implements new web APIs. Other new features include a redesigned download manager, a new "Places" system for storing bookmarks and history, and separate themes for different operating systems. Tabbed browsing was more popularised in this version. The final version under 3.0 is Firefox 3.0.19.

Development stretches back to the first Firefox 3 beta (under the codename 'Gran Paradiso') which had been released several months earlier on November 19, 2007, and was followed by several more beta releases in spring 2008 culminating in the June release. Firefox 3 had more than 8 million unique downloads the day it was released, setting a Guinness World Record.

Release history of Firefox 3
Version	Codename	Release date	Release type and highlights
3.0	Gran Paradiso	June 17, 2008	Official version 3.0 release. Gecko version 1.9 One-click site info Malware Protection New Web Forgery Protection page New SSL error pages Add-ons and Plugin version check Secure add-on updates Anti-virus integration with download manager Vista Parental Controls Effective top-level domain (eTLD) service better restricts cookies and other restricted content to a single domain. Better protection against cross-site JSON data leaks. Easier password management – save passwords after successful login Simplified add-on installation from third party’s New Download Manager Resumable downloading after closing the browser Full page zoom Podcasts and Videocasts can be associated with your media playback tools Tab scrolling and quickmenu Save what you were doing – Firefox 3 will prompt users to save tabs on exit. Optimized Open in Tabs behavior Location and Search bar size can now be customized with a simple resizer item. Text selection improvements (select multiple selections of text) Find toolbar: the Find toolbar now opens with the current selection. Plugin management with the add-on manager Improved integration with Windows Improved integration with the Mac Integration with Linux GTK theme Bookmark star button Bookmark tags Smart Location Bar Library of bookmarks, history, etc. Smart Bookmark Folders Web-based protocol handlers for mail:to Download & Install Add-ons from the Add-on manager Easy to use Download Actions New graphics and font handling in Gecko 1.9 provide rendering improvements in: CSS SVG Display of fonts with ligatures and complex scripts Color management of images with capabilities Offline support for web applications Improved speed Reduced memory usage Increased reliability 25000 total code changes Security fixes Stability fixes Changes during alphas Cairo graphics library. Cocoa Widgets in OS X builds. Updated threading model. Changes to how DOM events are dispatched, how HTML object elements are loaded, and how web pages are painted. New SVG elements and filters, and improved SVG specification compliance. Windows 95, 98, ME and Mac OS X v10.2 no longer supported. Moving DOM nodes between documents require a call to importNode or adoptNode as per the DOM specification. Reflow refactoring (leading to Acid2 test compliance) among numerous layout bug fixes. Web Apps 1.0 API for changing stylesheets support. Inline-block and inline-table values of CSS 2.1's display property implemented. XML documents can be rendered during download. Greatly improved Mac widgets support since Alpha 1. Improvements in Cairo graphics layer. Non-standard JavaScript "Script" object no longer supported. Support for allowing web pages to store resources in the browser's offline cache. Support for Animated PNG images. Support for the "HTTPOnly" cookie extension which provides enhanced cookie privacy (also backported to Firefox 2.0.0.5). Improvements to layout and scaling precision across numerous screen and printer resolutions. Adding of FUEL JavaScript library for extension developers. Rewrite of Page Info dialog. Upgrade to Cairo 1.4.2. More Cocoa regression fixes. Places (bookmark and history service based on SQLite) used by default, but no front-end changes. Breakpad used as crash reporter on Windows and Mac OS X, superseding closed-source Talkback. Password manager rewrite. Support for Growl and native widgets within forms for Mac OS X. Upgrade of SQLite to version 3.3.17, leading to increased cookie performance due to transition of cookie service to SQLite. Site-specific preference service, used initially for text zoom, allowing zoom setting to remain on each website. Support for native widgets within forms for Linux. New Quit dialog handles multiple windows more elegantly and allows users to save session. Autoscroll rewrite: numerous bug fixes and significant performance gain. Fixes to the use of units within the download manager. Various Places bug fixes. More APIs implemented from WHATWG specs, such as ability to read files from file selection fields without need to upload and cut/copy/paste events, and cross-site XMLHttpRequest. New protocol-handling dialog. Experimental full-page zoom support, but no UI to control it. Numerous Mac OS X bug fixes, but Mac OS X 10.3 no longer supported for Gecko 1.9. General bug fixes. New, basic UI for tagging bookmarks. Remember password prompt changed to non-modal information bar. Malware blacklist support. New UI for FTP and File protocol listings. Applications pane added to preferences. Basic support for web-based protocol handlers. Changes during betas New UI improvements, including redesigned location bar, Places Organizer, Smart Bookmarks. Various stability and performance improvements. New UI improvements, including redesigned buttons and location bar. Different default native themes for each operating system. Upgraded to SQLite 3.5.4. Various stability and performance improvements. New UI improvement, including improved default themes for different operating systems. Various improvements in speed and resource usage. Further improved themes to match various operating systems, JavaScript engine optimizations for speed, improved Places organizer.
3.0.1		July 16, 2008	Security and stability update.
3.0.2		September 23, 2008	Regular security and stability update.
3.0.3		September 26, 2008	Bug fix for retrieving and saving passwords.
3.0.4		November 12, 2008	Regular security and stability update.
3.0.5		December 16, 2008	Regular security and stability update.
3.0.6		February 3, 2009	Regular security and stability update.
3.0.7		March 4, 2009	Regular security and stability update.
3.0.8		March 27, 2009	Off-cycle security update.
3.0.9		April 21, 2009	Regular security and stability update.
3.0.10		April 27, 2009	Off-cycle stability update.
3.0.11		June 11, 2009	Regular security and stability update.
3.0.12		July 21, 2009	Regular security and stability update.
3.0.13		August 3, 2009	Regular security and stability update.
3.0.14		September 9, 2009	Regular security and stability update.
3.0.15		October 27, 2009	Regular security and stability update.
3.0.16		December 15, 2009	Regular security and stability update.
3.0.17		January 5, 2010	Off-cycle stability update.
3.0.18		February 17, 2010	Regular security and stability update.
3.0.19		March 30, 2010	Regular security and stability update. Fixed several security and stability issues. End-of-life 3.0.x product line

Firefox 3.5

Firefox 3.5 on Ubuntu

Main article: Firefox 3.5

Version 3.5, codenamed Shiretoko, adds a variety of new features to Firefox. Initially numbered Firefox 3.1, Mozilla developers decided to change the numbering of the release to 3.5 in order to reflect a significantly greater scope of changes than originally planned. The final release was on June 30, 2009. The changes included much faster performance thanks to an upgrade to SpiderMonkey JavaScript engine called TraceMonkey and rendering improvements, and support for the <video> and <audio> tags as defined in the HTML5 specification, with a goal to offer video playback without being encumbered by patent problems associated with many video technologies. Cross-site XMLHttpRequests (XHR), which can allow for more powerful web applications and an easier way to implement mashups, are also implemented in 3.5. A new global JSON object contains native functions to efficiently and safely serialize and deserialize JSON objects, as specified by the ECMAScript 3.1 draft. Full CSS 3 selector support has been added. Firefox 3.5 uses the Gecko 1.9.1 engine, which includes a few features that were not included in the 3.0 release. Multi-touch trackpad support was also added to the release, including gesture support like pinching for zooming and swiping for back and forward. Firefox 3.5 also features an updated logo.

Release history of Firefox 3.5
Version	Codename	Release date	Release type and highlights
3.5	Shiretoko	June 30, 2009	Official version 3.5 release. Gecko version 1.9.1 Support for the HTML5 <video> and <audio> elements including native support for Ogg Theora video and Vorbis audio Improved tools for controlling your private data, including a Private Browsing Mode Better web application performance using the new TraceMonkey JavaScript engine The ability to share your location with websites using Location Aware Browsing Support for native JSON, and web worker threads Improvements to the Gecko layout engine, including speculative parsing for faster content rendering Support for new web technologies such as: Downloadable fonts CSS media queries New transformations and properties JavaScript query selectors HTML5 local storage and offline application storage <canvas> text ICC profiles SVG transforms. Changes during alphas Web standards improvements. Text API for the <canvas> element. Support for using border images. Support for DOM query selectors. Improvements to Smart Location Bar. New tab-switching behavior. Changes during betas Web standards improvements in Gecko layout engine. Added support for CSS 2.1 and CSS 3 properties. New tab-switching shortcut that shows previews of the tab user is switching to. Improved control over Smart Location Bar using special characters to restrict your search. Support for new web technologies. Available in 54 languages. Added new Private Browsing Mode. Added functions to facilitate clearing recent history by time as well as to remove all traces of a website. New support for web worker threads. New TraceMonkey JavaScript engine on by default for web content. Improvements to Gecko layout engine, including speculative parsing for faster content rendering. Removed new tab-switching behavior based on user feedback. Support for new web technologies. Available in 64 languages. Improved new Private Browsing Mode. Improvements to web worker thread support. Improved performance and stability with the TraceMonkey JavaScript engine. New native JSON support. Improvements to Gecko layout engine, including speculative parsing for faster content rendering. Support for new web technologies such as <video> and <audio> elements, W3C Geolocation API, JavaScript query selectors, CSS 2.1 and 3 properties, SVG transforms and offline applications. Available in 70 languages. Improved tools for controlling private data, including Private Browsing Mode. Better performance and stability with new TraceMonkey JavaScript engine. Ability to provide Location Aware Browsing using web standards for geolocation. Support for native JSON, and web worker threads. Improvements to Gecko layout engine, including speculative parsing for faster content rendering. Support for new web technologies such as HTML5 <video> and <audio> elements, downloadable fonts and other new CSS properties, JavaScript query selectors, HTML5 offline data storage for applications, and SVG transforms.
3.5.1		July 16, 2009	Off-cycle security and stability update.
3.5.2		August 3, 2009	Regular security and stability update.
3.5.3		September 9, 2009	Regular security and stability update.
3.5.4		October 27, 2009	Regular security and stability update.
3.5.5		November 5, 2009	Off-cycle security and stability update.
3.5.6		December 15, 2009	Regular security and stability update.
3.5.7		January 5, 2010	Off-cycle stability update.
3.5.8		February 17, 2010	Regular security and stability update.
3.5.9		March 30, 2010	Regular security and stability update.
3.5.10		June 22, 2010	Regular security and stability update.
3.5.11		July 20, 2010	Regular security and stability update.
3.5.12		September 7, 2010	Regular security and stability update.
3.5.13		September 15, 2010	Off-cycle stability update.
3.5.14		October 19, 2010	Regular security and stability update.
3.5.15		October 27, 2010	Off-cycle security update.
3.5.16		December 9, 2010	Regular security and stability update.
3.5.17		March 1, 2011	Regular security and stability update.
3.5.18		March 22, 2011	Off-cycle security update. Blacklists a few invalid HTTPS certificates.
3.5.19		April 28, 2011	Regular security and stability update. Fixed several security issues Fixed several stability issues End-of-life 3.5.x product line

Firefox 3.6

Main article: Firefox 3.6

Version 3.6, released on January 21, 2010, uses the Gecko 1.9.2 engine and includes several interface improvements, such as "personas". This release was referred to as 3.2 before 3.1 was changed to 3.5. The codename for this version was Namoroka. This is the last major, official version to run on PowerPC-based Macintoshes.

One minor update to Firefox 3.6, version 3.6.4 (code-named Lorentz) is the first minor update to make non-intrusive changes other than minor stability and security fixes. It adds Out of Process Plugins (OOPP), which runs plugins in a separate process, allowing Firefox to recover from plugin crashes. Firefox 3.6.6 lengthens the amount of time a plugin is allowed to be unresponsive before the plugin quits.

Support for Firefox 3.6 ended on April 24, 2012.

Release history of Firefox 3.6
Version	Codename	Release date	Release type and highlights
3.6	Namoroka	January 21, 2010	Official Firefox 3.6 release. Gecko version 1.9.2 Support for Persona themes Protection from out-of-date plugins to keep users safer as they browse. Open, native video can now be displayed full screen and supports poster frames. Improved JavaScript performance, overall browser responsiveness, and startup time. The ability for web developers to indicate that scripts should run asynchronously to speed up page load times. Continued support for downloadable web fonts using the new WOFF font format. Support for new CSS attributes such as gradients, background sizing, and pointer events. Support for new DOM and HTML5 specifications including the Drag & Drop API and the File API, which allow for more interactive web pages. Changes to how third-party software can integrate with Firefox in order to prevent crashes. Changes during alphas Compositor (Phase 1), which moves Gecko to using one native widget per top-level content document. A new focus model. The chromedir attribute has been replaced with a pseudoclass. Several new CSS3 properties including background size and gradients for background images. Speed improvements to the TraceMonkey JavaScript engine. Startup and responsiveness improvements throughout the application. Changes during betas Users can now change their browser’s appearance with a single click, with built in support for Personas. Firefox 3.6 will alert users about out of date plugins to keep them safe. Open, native video can now be displayed full screen, and supports poster frames. Support for the WOFF font format. Improved JavaScript performance, overall browser responsiveness and startup time. Support for new CSS, DOM and HTML5 web technologies. A mechanism to prevent incompatible software from crashing Firefox. A change to how third-party software integrates with Firefox to increase stability. The ability to run scripts asynchronously to speed up page load times. Added support for the HTML5 File API.
There was no version 3.6.1.
3.6.2		March 22, 2010	Security and stability update.
3.6.3		April 1, 2010	Quick turn-around security update.
3.6.3plugin1	Lorentz	April 8, 2010	First Firefox "Lorentz" beta, followed by 7 more Firefox 3.6.4 pre-release builds, all codenamed "Lorentz".
3.6.4 (OOPP)	Lorentz	June 22, 2010	Regular security and stability update, including OOPP.
There was no version 3.6.5.
3.6.6		June 26, 2010	Off-cycle stability update. Modified crash protection feature to increase amount of time plugins allowed to be non-responsive before being terminated.
3.6.7		July 20, 2010	Regular security and stability update.
3.6.8		July 23, 2010	Off-cycle stability update.
3.6.9		September 7, 2010	Regular security and stability update. Also added support for X-FRAME-OPTIONS HTTP response header to help prevent clickjacking and removed option to enable experimental HTML5 parser via user preference html5.enable in about:config.
3.6.10		September 15, 2010	Off-cycle stability update.
3.6.11		October 19, 2010	Regular security and stability update.
3.6.12		October 27, 2010	Off-cycle security update.
3.6.13		December 9, 2010	Regular security and stability update.
3.6.14		March 1, 2011	Regular security and stability update.
3.6.15		March 4, 2011	Off-cycle stability update. Fixed issue where some Java applets failed to load in Firefox 3.6.14.
3.6.16		March 22, 2011	Off-cycle security update. Blacklisted several invalid HTTPS certificates.
3.6.17		April 28, 2011	Regular security and stability update.
3.6.18		June 21, 2011	Regular security and stability update.
3.6.19		July 11, 2011	Off-cycle stability update. Turned off downloadable font support for users running Mac OS X 10.7 due to an underlying platform bug. No changes made on Windows side.
3.6.20		August 16, 2011	Regular security and stability update.
3.6.21		August 30, 2011	Off-cycle security update. Blacklisted a compromised HTTPS certificate.
3.6.22		September 6, 2011	Off-cycle security update.
3.6.23		September 27, 2011	Regular security and stability update.
3.6.24		November 8, 2011	Regular security and stability update.
3.6.25		December 20, 2011	Regular security and stability update.
3.6.26		January 31, 2012	Regular security and stability update.
3.6.27		February 17, 2012	Off-cycle security update.
3.6.28		March 13, 2012	Regular security and stability update. Last release for Mac OS X Tiger and PowerPC Macs Added Out-of-process plugins Fixed several security issues Fixed several stability issues End-of-life 3.6.x product line on April 24, 2012.

Firefox 4

Firefox 4.0 displaying Wikipedia on Windows 7

Main article: Firefox 4

On October 13, 2006, Brendan Eich, Mozilla's then Chief Technology Officer, wrote about the plans for "Mozilla 2", referring to the most comprehensive iteration (since its creation) of the overall platform on which Firefox and other Mozilla products run. Most of the objectives were gradually incorporated into Firefox through versions 3.0, 3.5, and 3.6. The largest changes, however, were planned for Firefox 4.

Firefox 4 was released on March 22, 2011, originally Firefox 3.7 (Gecko 1.9.3) during its alpha stage, brought a new user interface and is said to be faster. Early mockups of the new interface on Windows, Mac OS X, and Linux were first made available in July 2009. Other new features included improved notifications, tab groups, application tabs, a redesigned add-on manager, integration with Firefox Sync, and support for multi-touch displays.

Firefox 4 was based on the Gecko 2.0 engine, which added or improved support for HTML5, CSS3, WebM, and WebGL. It also included a new JavaScript engine (JägerMonkey) and better XPCOM APIs.

Release history of Firefox 4
Version	Codename	Release date	Release type and highlights
4.0	Tumucumaque	March 22, 2011	Official Firefox 4.0 release. Gecko version 1.9.3 Firefox 4 is available in over 80 languages Uses JägerMonkey, a faster JavaScript engine Support for Do Not Track ("DNT") header that allows users to opt out of behavioral advertising Firefox Sync is included by default Graphic rendering is now hardware-accelerated using Direct3D 9 (Windows XP), Direct3D 10 (Windows Vista & 7), and OpenGL on Mac OS Direct2D Hardware Acceleration is now on by default for Windows 7 users WebGL is enabled on all platforms that have a capable graphics card with updated drivers Native support for the HD HTML5 WebM video format, hardware accelerated where available Firefox button has a new look for Windows Vista and Windows 7 users Tabs are now on top by default on Windows, Mac OS X, and Linux You can search for and switch to already open tabs in the Smart Location Bar The stop and reload buttons have been merged into a single button on Windows, Mac OS X, and Linux The Bookmarks Toolbar has been replaced with a Bookmarks Button by default (you can switch it back if you'd like) Crash protection when there is a crash in Adobe Flash Player, Apple QuickTime or Microsoft Silverlight plugins You can turn any tab into an "App Tab" The default homepage design has been refreshed Overhaul of the bookmarks and history code, enabling faster bookmarking and startup performance Per-compartment garbage collection is now enabled, reducing work done during complex animations Additional polish for the Firefox add-on Manager Improved web typography using OpenType with support for ligatures, kerning and font variants Web developers can animate content using CSS Transitions Responsiveness and scrolling improvements from the new retained layers layout system HTML5 Forms API makes web based forms easier to implement and validate Support for the new proposed Audio Data API Support for HSTS security protocol allowing sites to insist that they only be loaded over SSL A new feature called Panorama gives users a visual overview of all open tabs, allowing them to be sorted and grouped An experimental API is included to provide more efficient JavaScript animations Firefox now supports the HTML5 video "buffered" property Changes to how XPCOM components are registered in order to help startup time and process separation New Addons Manager and extension management API Significant API improvements are available for JS-ctypes, a foreign function interface for extensions CSS Transitions are partially supported Core Animation rendering model for plugins on Mac OS X Web developers can update the URL field without reloading the page using HTML History APIs More responsive page rendering using lazy frame construction Link history lookup is done asynchronously to provide better responsiveness during pageload CSS :visited selectors have been changed to block websites from being able to check a user's browsing history New HTML5 parser Support for more HTML5 form controls Web authors can now get touch events from Firefox users on Windows 7 machines A new way of representing values in JavaScript that allows Firefox to execute heavy, numeric code more efficiently. Changes during alphas Support for WebGL(Disabled by default, but can be enabled by changing a preference). Support for new CSS, DOM and HTML5 web technologies. On Windows and Linux, plugins (such as Flash and Silverlight) are now isolated from Firefox. Plugin crashes will not kill Firefox itself, and unresponsive plugins are automatically restarted. The SSL security system has been changed to fix a renegotiation flaw. Link history lookup is now performed asynchronously on a thread. Loading the HTML5 specification no longer causes very long browser pauses. Some JavaScript engine improvements. The stop and reload buttons have been merged when they are adjacent on the toolbar. More performance and stability improvements. An experimental Direct2D rendering backend on Windows is available, turned off by default. Significant API improvements are available for JS-ctypes. Mozilla now uses an infallible allocator. Additional fixes for multi-process plugins. CSS :visited selectors have been changed to block ways that websites can quickly check a user's browsing history. Currently loaded web pages are shown in the location bar autocomplete list, allowing switching to existing tabs. The beta version of Adobe Flash is now run in a separate process on Mac OS X Snow Leopard (10.6). Full-screen video on Windows is now rendered using hardware acceleration when available. Mozilla has implemented the Core Animation rendering model for plugins on Mac OS X. Linux builds are now built with -fomit-frame-pointer. Support for new SVG and HTML5 web technologies. Added WebM video playback. First official release to include linux-x86_64 and mac-x86_64 builds and first regular release to include WebM video playback. New Addons Manager (placeholder UI only). Tab on Top can now be implemented. Firefox now uses hardware acceleration for video playback. Cocoa NPAPI support. ChromeWorker with jsctypes support. Lazy frame construction for faster dynamic pages. JavaScript performance improvements. Loading the URL about:memory now shows how much memory is used by different parts of Firefox. More Performance improvement and support for new CSS and HTML5 web technology. Changes during betas Tabs are now on top by default on Windows. On Windows Vista and Windows 7 the menu bar has been replaced with the Firefox button. The Bookmarks Toolbar has been replaced with a Bookmarks Button by default (you can switch it back if you'd like). Support for more HTML5 technologies. Tabs are now on top by default on OSX. App Tabs can now be created. Content animation using CSS Transitions can now be implemented. Responsiveness and scrolling improvements from the new retained layers layout system. JavaScript speed improvements due to engine optimizations. Changes to how XPCOM components are registered in order to help startup time and process separation. Web authors can now get touch events from Firefox users on Windows 7 machines. A new way of representing values in JavaScript that allows Firefox to execute heavy, numeric code (used for things like graphics and animations) more efficiently. Firefox Sync is now included. Panorama, a new feature that gives users a visual overview of all open tabs, allowing them to be sorted and grouped, is now included. An experimental API is included to provide more efficient Javascript animations. Firefox now supports the HTML5 video "buffered" property. Support for the new proposed Audio Data API. Direct2D Hardware Acceleration is now on by default for Windows 7 users. Firefox button has a new look for Windows Vista and Windows 7 users. Support for HSTS security protocol allowing sites to insist that they only be loaded over SSL. Fixed a stability issue affecting Windows users. Fixed an issue causing rendering errors with plugins affecting Mac OS X users. Uses JägerMonkey, a new, faster JavaScript engine. WebGL is enabled by default on Windows and Mac OS X. Certain rendering operations are now hardware-accelerated using Direct3D 9 on Windows XP, Direct3D 10 on Windows Vista and 7, and OpenGL on Mac OS X. Improved web typography using OpenType with support for ligatures, kerning and font variants. HTML5 Forms API makes web based forms easier to implement and validate. The Firefox Sync setup experience has been greatly improved across desktop and mobile devices. Speed, functionality, and compatibility improvements to WebGL. Additional polish for the Firefox Add-ons Manager. Overhaul of the bookmarks and history code, enabling faster bookmarking and startup performance. Per-compartment garbage collection is now enabled, reducing work done during complex animations. Compatibility and stability improvements when using Adobe Flash on Mac OS X. Improvements in memory usage. Support for a graphics driver blacklist to improve stability. Support for the proposed Do Not Track ("DNT") header. Connection status messages are now shown in a small overlay. WebGL has been re-enabled on Linux. The default homepage design has been refreshed. Firefox no longer switches into offline mode automatically. Increased performance while viewing Flash content. Improved plugin compatibility with hardware acceleration enabled. Hovering over links now displays the URL at the bottom of the window rather than in the location bar. General stability, performance, and compatibility improvements. Changes during release candidates General stability, performance, and compatibility improvements. Blacklisted a few invalid HTTPS certificates. Updated localizations for 29 locales. Added Vietnamese localization, bringing the total languages available in Firefox 4 to 83.
4.0.1	Macaw	April 28, 2011	Regular security and stability update. Fixed several security issues Fixed several stability issues End-of-life 4.0.x product line on June 21, 2011.

Rapid releases

Firefox 5 through 9

In April 2011, the development process was split into several "channels", each working on a build in a different stage of development. The most recent available build is called "Nightly Builds" and offers the latest, untested features and updates. The "Aurora" build is up to six weeks behind "Nightly" and offers functionality that has undergone basic testing. As of version 35, the "Aurora" channel has been renamed to the "Developer Edition" channel. The "Beta" channel is up to six weeks behind the "Aurora" build, for up to about twelve week period compared to the most recent "Nightly" build. The "Beta" channel provides improved stability over the "Nightly" builds and is the first development milestone that has the "Firefox" logo. "Release" is the current official version of Firefox. Gecko version numbering is same as Firefox build version number, starting 5.0 on Firefox 5.

New releases are planned to occur at six-week intervals. The stated aim of this faster-paced process is to get new features to users faster. This accelerated release cycle was met with criticism by users, as it often broke add-on compatibility, as well as those who believe Firefox was simply trying to increase its version number to compare with other browsers such as Google Chrome.

Firefox 5 was released on June 21, 2011, three months after the major release of Firefox 4. Firefox 5 is the first release in Mozilla's new rapid release plan, matching Google Chrome's rapid release schedule and rapid version number increments. Version 5 significantly improved the speed of web-related tasks, such as loading pages with combo boxes or MathML. Mozilla also integrated the HTML5 video WebM standard into the browser, allowing playback of WebM video.

Firefox 6 released on August 16, 2011, introducing permissions manager, new address bar highlighting (the domain name is black while the rest of the URL is gray), streamlining the look of the site identity block, quicker startup time, a ScratchPad JavaScript compiler, and many other new features. This update also brought the infamous feature that JavaScript entered in the address bar does not run.

Firefox 7 released September 27, 2011, uses as much as 50% less RAM than Firefox 4 as a result of the MemShrink project to reduce Firefox memory usage. Mozilla Firefox 7.0.1 was released a few days later, fixing a rare, but serious, issue with add-ons not being detected by the browser. Some URLs are trimmed in the address bar, so the "http://" scheme no longer appears, but "https://" is still displayed. Trailing slashes on domains are also hidden, for example: https://www.example.org/ becomes https://www.example.org.

Firefox 8 released on November 8, 2011 prompts users about any previously installed add-ons. Upon installation, a dialog box prompted users to enable or disable the add-ons. Add-ons installed by third-party programs were disabled by default, but user-installed add-ons were enabled by default. Mozilla judged that third-party-installed add-ons were problematic, taking away user control, lagging behind on compatibility and security updates, slowing down Firefox startup and page loading time, and cluttering the interface with unused toolbars.

Firefox 9 released on December 20, 2011 and 9.0.1 a day later, includes various new features such as Type Inference, which boosts JavaScript performance up to 30%, improved theme integration for Mac OS X Lion, added two finger swipe navigation for Mac OS X Lion, added support for querying Do Not Track status via JavaScript, added support for font-stretch, improved support for text-overflow, improved standards support for HTML5, MathML, and CSS, and fixed several security problems. It also features a large list of bug fixes.

Release history of Firefox 5 – 9
Version	Release date	Release type and highlights
5.0	June 21, 2011	Official Firefox 5.0 release. Better standards support for HTML5, CSS3, MathML, XHR and SMIL Better visibility for the Do not track header preference Stability and security improvements Better tuned HTTP idle connection logic Improved canvas, JavaScript, memory, and networking performance Improved spell checking for some locales Improved desktop environment integration for Linux users Better WebGL security (WebGL content can no longer load cross-domain textures). Background tabs have setTimeout and setInterval clamped to 1000 ms to improve performance Gecko version number bumped to 5.0 to match (and from then on stay synced to) Firefox's major version number. Added support for CSS animations. The Do-Not-Track header preference has been moved to increase discoverability. Tuned HTTP idle connection logic for increased performance. Improved canvas, JavaScript, memory, and networking performance. Improved standards support for HTML5, XHR, MathML, SMIL, and canvas. Improved spell checking for some locales. Improved desktop environment integration for Linux users. WebGL content can no longer load cross-domain textures. Background tabs have setTimeout and setInterval clamped to 1000 ms to improve performance.
5.0.1	July 11, 2011	Off-cycle stability update for Mac OS X only. Fixed an issue in Mac OS X 10.7 that could cause Firefox to crash Fixed an issue caused by Apple's "Java for Mac OS X 10.6 Update 5" where the Java plugin would not be loaded End-of-life 5.0.x product line on August 16, 2011.
6.0	August 16, 2011	Official Firefox 6.0 release. about:permissions, a permissions manager. The user can choose what information can be shared with sites, e.g. location. The address bar now highlights the domain of the website you're visiting. Streamlined the look of the site identity block. Added support for the latest draft version of WebSockets with a prefixed API. Added support for EventSource / server-sent events. Added support for window.matchMedia. Added Scratchpad, an interactive JavaScript prototyping environment. Added a new Web Developer menu item and moved development-related items into it. Improved usability of the Web Console. Improved the discoverability of Firefox Sync. Reduced browser startup time when using Panorama. Fixed several stability and security issues.
6.0.1	August 30, 2011	Off-cycle security update. Revoked the root certificate for DigiNotar due to fraudulent SSL certificate issuance.
6.0.2	September 6, 2011	Off-cycle security update. Removed trust exceptions for certificates issued by Staat der Nederlanden Resolved an issue with gov.uk websites. Last release for Android 2.0 End-of-life 6.0.x product line on September 27, 2011.
7.0	September 27, 2011	Official Firefox 7.0 release. Drastically improved memory handling for certain use cases. Added a new rendering backend to speed up Canvas operations on Windows systems. Bookmark and password changes now sync almost instantly when using Firefox Sync. The http:// URL prefix is now hidden by default. Added support for text-overflow: ellipsis. Added support for the Web Timing specification. Enhanced support for MathML. The WebSocket protocol has been updated from version 7 to version 8. Added an opt-in system for users to send performance data back to Mozilla to improve future versions of Firefox. Fixed several security and stability issues. Last release for Maemo
7.0.1	September 29, 2011	Off-cycle security and stability update. Fixed a rare issue where some users could find one or more of their add-ons hidden after a Firefox update. End-of-life 7.0.x product line on November 8, 2011.
8.0	November 8, 2011	Official Firefox 8.0 release. Add-ons installed by third-party programs are now disabled by default. Added a one-time add-on selection dialog to manage previously installed add-ons. Added Twitter to the search bar. Added a preference to load tabs on demand, improving startup time when windows are restored. Improved performance and memory handling when using <audio> and <video> elements. Added Cross-Origin Resource Sharing (CORS) support for cross-domain textures in WebGL. Added support for HTML5 context menus. Added support for insertAdjacentHTML(). Improved CSS hyphen support for many languages. Improved WebSocket support. Changes during betas Removed support for new tab animation due to incompatibilities with some extensions.
8.0.1	November 21, 2011	Off-cycle security and stability update. Fixed Mac OS X crash that occurred in certain instances when a Java Applet is loaded with Java SE 6 version 1.6.0_29 installed. Fixed Windows startup crash caused by RoboForm versions older than 7.6.2. End-of-life 8.0.x product line on December 20, 2011.
9.0	December 20, 2011	Official Firefox 9.0 release. Added type inference, significantly improving JavaScript performance. Improved theme integration for Mac OS X Lion. Added two finger swipe navigation for Mac OS X Lion. Added support for querying Do Not Track status via JavaScript. Added support for the font-stretch CSS property. Improved support for the text-overflow CSS property. Improved standards support for HTML5, MathML, and CSS.
9.0.1	December 21, 2011	Off-cycle security and stability update. Fixed crash on Windows, Mac and Linux End-of-life 9.0.x product line on January 31, 2012.

Firefox 10 through 16

Firefox 10 and Firefox ESR 10 were released on January 31, 2012. Firefox 10 ESR is the first Extended Support Release (ESR) as previosuly in January 10, 2012, where the Mozilla Foundation announced the availability of an ESR version of Firefox. Firefox 10 hides the forward arrow button until there is a website to go forward to, or it is manually activated. Firefox 10 adds a Full Screen API and improved WebGL performance. Firefox 10 assumed all add-ons made for at least Firefox 4 were compatible. The add-on developer is able to alert Mozilla that the add-on is incompatible, overriding compatibility with version 10 or later. This new rule also does not apply to themes.

Firefox 11 was released on March 13, 2012. Firefox 11 introduced many new features, including migration of bookmarks and history from Google Chrome, SPDY integrated services, Page Inspector Tilt (3D View), Add-on Sync, redesigned HTML5 video controls, and the Style Editor (CSS). The update also fixed many bugs, and improved developer tools.

Firefox 12 was released on April 24, 2012. Firefox 12 introduced few new features, but it made many changes and laid the ground work for future releases. Firefox 12 for Windows added the Mozilla Maintenance Service which can update Firefox to a newer version without UAC prompt. It also added line numbers in the "Page Source" and centered find in page results. There were 89 improvements to Web Console, Scratchpad, Style Editor, Page Inspector, Style Inspector, HTML view and Page Inspector 3D view (Tilt). Many bugs were fixed, as well as many other minor under-the-hood changes. Firefox 12 is the final release to support Windows 2000 and Windows XP RTM & SP1.

Firefox 13 was released on June 5, 2012. Starting with this version, Windows support was exclusively for Windows XP SP2/SP3, Windows Vista, and Windows 7. Firefox 13 adds and updates several features, such as an updated new tab and home tab page. The updated new tab page is a feature similar to the Speed Dial already present in Opera, Google Chrome, Apple Safari, and Internet Explorer. The new tab page will display nine of the user's most visited websites, along with a cached image. In addition to the updated new tab and home tab page, Mozilla has added a user profile cleaner/reset, reduced hang times, and implemented tabs on demand. The user profile cleaner/reset provides a way for users to fix Firefox errors and glitches that may occur. Mozilla's tabs on demand restores tabs that were open in the previous session, but will keep the tabs unloaded until the user requests to view the page.

Firefox 14 version 1.4.0 for Android was released on June 26, 2012, just outside the regular release schedule of the web browser. In order to sync the version numbers of the desktop and mobile version of Firefox, Mozilla decided to release Firefox 14.0.1 for mobile and desktop on July 17, 2012, instead of Firefox 14.0 for the desktop and Firefox 14.0.1 for mobile clients.

Firefox 14 introduces a new hang detector (similar to how Mozilla currently collects other data) allows Mozilla to collect, analyze, and identify the cause of the browser freezing/hanging. Mozilla will use this information to improve the responsiveness of Firefox for future releases. In addition to tackling freezing and not-responding errors that occur because of Firefox, Mozilla implemented opt-in activation for plugins such as Flash and Java. Mozilla wants to reduce potential problems that could arise through the unwanted use of third-party applications (malware, freezing, etc.).

Firefox 15 was released on August 28, 2012. This version includes a "Responsive Design View" developer tool, adds support for the Opus audio format, and adds preliminary native PDF support (disabled by default).

Firefox 15 introduced silent updates, an automatic update that will update Firefox to the latest version without notifying the user, a feature that the web browsers Google Chrome and Internet Explorer 8 and above have already implemented, although the user was able to disable that function. The startup time in Firefox 15 was improved for Windows users.

Firefox 16 was released on October 9, 2012, fixing outstanding bugs of the new features in Mac OS X Lion. There was an improvements made to startup speed when a user wants to restore a previous session. Support for viewing PDF files inline was added in placement of a plugin. Support for web apps was added. Opus audio format is now enabled by default.

The roll-out of Firefox 16 revision 16.0.0 was stopped on October 10, 2012, after Mozilla detected a security flaw and recommended downgrading to 15.0.1 until the issue could be fixed. The security flaw was fixed in version 16.0.1, which was released the following day, October 11, 2012. Version 16.0.2 was released October 26, 2012. It fixed additional security issues, and is also the final release to support Mac OS X Leopard.

Release history of Firefox 10 – 16
Version	Release date	Release type and highlights
10.0	January 31, 2012	Official Firefox 10.0 release. First Extended Support Release (ESR). Most add-ons are now compatible with new versions of Firefox by default. Anti-Aliasing for WebGL is now implemented. CSS3 3D-Transforms are now supported. New <bdi> element for bi-directional text isolation, along with supporting CSS properties. Full Screen APIs allow you to build a web application that runs full screen.
10.0esr
10.0.1	February 10, 2012	Off-cycle security and stability update.
10.0.1esr
10.0.2	February 16, 2012	Off-cycle security and stability update. Fixed Java applets that sometimes caused text input to become unresponsive. End-of-life 10.0.x product line on March 13, 2012.
10.0.2esr
10.0.3esr	March 13, 2012	Regular security and stability update. Security fixes Fixed web workers running out of memory, affecting some add-ons used by organizations.
10.0.4esr	April 24, 2012	Regular security and stability update. Fixed an issue in Firefox ESR 10.0.3 that caused the "Whats New" page to open after an update. Fixed extensions.checkCompatibility.* prefs not working in ESR releases.
10.0.5esr	June 5, 2012	Regular security and stability update. Fixed the 10.0.5 Firefox top crash with signature [@ GLEngine@0x620cf ].
10.0.6esr	July 17, 2012	Regular security and stability update. Fixed some text editing inconsistencies.
10.0.7esr	August 28, 2012	Regular security and stability update. Fixed contenteditable breaks in 10.0.7 that middle-click to open links. Addressed a fix that allows specifying wildcard that matches all simple netbiosnames in network.automatic-ntlm-auth.trusted-uris.
10.0.8esr	October 9, 2012	Regular security and stability update.
10.0.9esr	October 12, 2012	Off-cycle security update.
10.0.10esr	October 26, 2012	Off-cycle security update.
10.0.11esr	November 20, 2012	Off-cycle security update.
10.0.12esr	January 8, 2013	Regular security update. End-of-life 10.0.x ESR product line on February 19, 2013.
11.0	March 13, 2012	Official Firefox 11.0 release. Migration of settings from Google Chrome. SPDY protocol support (disabled by default). RFC 6455 WebSocket protocol support with an unprefixed API. Page Inspector Tilt (3D View). Sync Add-ons. Redesigned HTML5 video controls. Style Editor (CSS). End-of-life 11.0.x product line on April 24, 2012.
12.0	April 24, 2012	Official Firefox 12.0 release. Windows: Firefox is now easier to update with one less prompt (User Account Control). Last release for Windows 2000. Reintroduced on-demand loading of pinned tabs after restoring a session. Page Source now has line numbers. Line breaks are now supported in the title attribute. Improvements to "Find in Page" to center search result. URLs pasted into the download manager window are now automatically downloaded. Support for the text-align-last CSS property has been added. Experimental support for ECMAScript 6 Map and Set objects has been implemented. Some TinyMCE-based editors failed to load. OS X: WebGL performance may be degraded on some hardware. End-of-life 12.0.x product line on June 5, 2012.
13.0	June 5, 2012	Official Firefox 13.0 release. When opening a new tab, users are now presented with their most visited pages. The default home page now has quicker access to bookmarks, history, settings, and more. SPDY protocol now enabled by default for faster browsing on supported sites. Restored background tabs are not loaded by default for faster startup. Smooth scrolling is now enabled by default. 72 total improvements to Page Inspector, HTML panel, Style Inspector, Scratchpad and Style Editor. The column-fill CSS property has been implemented. Experimental support for ECMAScript 6 Map and Set objects has been implemented. Support for the CSS3 background-position property extended syntax has been added. The :invalid pseudo-class can now be applied to the element. The CSS turn angle unit is now supported.
13.0.1	June 15, 2012	Off-cycle security and stability update. Fixed an issue when Windows Messenger did not load in Hotmail, and the Hotmail inbox did not auto-update. Fixed the Hebrew text that was sometimes rendered incorrectly. Fixed an issue in Adobe Flash 11.3 that sometimes caused a crash on quit. End-of-life 13.0.x product line on July 17, 2012.
14.0	June 26, 2012	Android Official Firefox Mobile 14.0 release. Google searches now utilize HTTPS. Full screen support for Mac OS X Lion implemented. Plugins can now be configured to only load on click (about:config). The Awesome Bar now auto-completes typed URLs, a new feature that will suggest a website that user frequently visits for a faster browsing. Improved site identity manager, to prevent spoofing of an SSL connection with favicons. Pointer Lock API implemented. New API to prevent your display from sleeping. New text-transform and font-variant CSS improvements for Turkic languages and Greek. Long URLs now extend the status bar almost to the whole width of the viewport. Optional Gstreamer backend for HTML5 video to allow H.264 playback. This allows playback of H.264 if the codec is installed as a GStreamer plugin. GStreamer support is not enabled in the official builds, but can be enabled at compile time.
14.0.1	July 17, 2012	Desktop Official Firefox Desktop 14.0 release. Fixed the GIF animation that can get stuck when src and image size are changed. Mac OS X: Fixed the nsCocoaWindow::ConstrainPosition that uses wrong screen in multi-display setup. Fixed the CSS :hover regression when an element's class name is set by JavaScript. End-of-life 14.0.x product line on August 28, 2012.
15.0	August 28, 2012	Official Firefox 15.0 release. Silent update: Background updates. Support for SPDY networking protocol v3. WebGL enhancements, including compressed textures for better performance. Localization in Maithili. Optimized memory usage for add-ons. JavaScript debugger integrated into developer tools. New layout view added to Inspector. High precision event timer implemented. The CSS word-break property has been implemented. New responsive design tool allows web developers to switch between desktop and mobile views of sites. Native support for the Opus audio format added. The <audio> and <video> elements now support the played attribute. The source element now supports the media attribute. Fixed the focus rings that keep growing when repeatedly tabbing through elements.
15.0.1	September 6, 2012	Off-cycle stability update. Addressed a fix where sites visited while in Private Browsing mode could be found through manual browser cache inspection. End-of-life 15.0.x product line on October 9, 2012.
16.0	October 9, 2012	Official Firefox 16.0 release. Firefox on Mac OS X now has preliminary VoiceOver support turned on by default. Initial web app support (Windows/Mac/Linux). Acholi and Kazakh localizations added. Improvements around JavaScript responsiveness through incremental garbage collection. New Developer Toolbar with buttons for quick access to tools, error count for the Web Console, and a new command line for quick keyboard access. CSS3 Animations, Transitions, Transforms and Gradients unprefixed. Recently opened files list in Scratchpad implemented. Fixed an issue where debugger breakpoints do not catch on page reload. No longer supporting MD5 as a hash algorithm in digital signatures. Opus support by default. Reverse animation direction has been implemented. Per tab reporting in about:memory. User Agent strings for pre-release Firefox versions now show only major version.
16.0.1	October 11, 2012	Off-cycle security and stability update.
16.0.2	October 26, 2012	Off-cycle security and stability update. Last release for Mac OS X Leopard (Intel) End-of-life 16.0.x product line on November 20, 2012.

Firefox 17 through 23

Logo used from Firefox 23 to Firefox 56

Firefox 17 and Firefox ESR 17 were released on November 20, 2012. It was not planned to bring as many user-facing features as previous releases, it brings improved display of location bar results, improvements to the silent update mechanism for users with incompatible add-ons, and refinements to the Click-To-Play system introduced in Firefox 14. A new feature for developers, an HTML tree editor is also included. Firefox 17 is the first version of the browser that uses SpiderMonkey 17.

Starting with Firefox 17, Mac OS X support is exclusively for Snow Leopard, Lion, and Mountain Lion.

Firefox 18 was released on January 8, 2013. A new feature for Firefox 18 is IonMonkey, Mozilla's next generation JavaScript engine, it also uses some functions of WebRTC.

Firefox 19 was released on February 19, 2013, featuring a built-in PDF viewer.

Firefox 20 was released on April 2, 2013, introduced a panel-based download manager, along with H.264 decoding on the <video> tag (on Windows only), and per-window private browsing (per-tab private browsing on Android). It also includes a new developer toolbox, that combines all developer tools into one panel.

Firefox 21 was released on May 14, 2013. The Social API now supports multiple providers, enhanced three-state UI for Do Not Track (DNT).

Firefox 22 was released on June 25, 2013. WebRTC is now enabled by default. Partial CSS Flexbox support added (flex-wrap support is currently scheduled for Firefox 28). A new feature for Firefox 22 was OdinMonkey, Mozilla's next generation JavaScript engine.

Firefox 23 was released on August 6, 2013. It includes an updated Firefox logo, mixed content blocking enabled by default to defend against man-in-the-middle attacks, implementation of the <input type="range"> form control attribute in HTML5, dropping support for the <blink> HTML element as well as text-decoration:blink CSS element, the restriction to have to "switch to a different search provider across the entire browser", and a global browser console, a new network monitor among other things. JavaScript is automatically enabled by the update, without regard to the previous setting, and the ability to turn it off has been removed from the interface; the "contentious" change was made because many websites depend on JavaScript and it was felt that users unaware that they had disabled JavaScript were attributing the resulting unpredictable layout to software bugs in Firefox.

Release history of Firefox 17 – 23
Version	Release date	Release type and highlights
17.0	November 20, 2012	Official Firefox 17.0 release. First revision of the Social API and support for Facebook Messenger. Click-to-play blocklisting implemented to prevent vulnerable plugin versions from running without the user's permission. Updated Awesome Bar experience with larger icons. Mac OS X 10.5 is no longer supported. JavaScript Maps and Sets are now iterable. SVG FillPaint and StrokePaint implemented. Improvements that make the Web Console, Debugger and Developer Toolbar faster and easier to use. New Markup panel in the Page Inspector allows easy editing of the DOM. Sandbox attribute for iframes implemented, enabling increased security. Over twenty performance improvements, including fixes around the New Tab page. Fixed pointer lock that doesn't work in web apps. Fixed page scrolling on sites with fixed headers.
17.0esr	November 20, 2012	Official Firefox 17.0 Extended Support Release (ESR).
17.0.1	November 30, 2012	Off-cycle stability update. Reverted user agent change causing some website incompatibilities. Fixed font rendering issue. End-of-life 17.0.x product line on January 8, 2013.
17.0.1esr	November 30, 2012	Off-cycle stability update.
17.0.2esr	January 8, 2013	Regular security and stability updates. Fixed improvements to the Click-to-Play vulnerable plugin blocklisting feature.
17.0.3esr	February 19, 2013	Regular security update.
17.0.4esr	March 7, 2013	Regular security update.
17.0.5esr	April 2, 2013	Regular security update.
17.0.6esr	May 10, 2013	Regular security update.
17.0.7esr	June 25, 2013	Regular security update.
17.0.8esr	August 6, 2013	Regular security update.
17.0.9esr	September 17, 2013	Regular security update.
17.0.10esr	October 29, 2013	Regular security update.
17.0.11esr	November 15, 2013	Off-cycle stability update. Updated ESR17 to NSS 3.14.5 RTM. End-of-life 17.0.x ESR product line on December 10, 2013.
18.0	January 8, 2013	Official Firefox 18.0 release. Faster JavaScript performance via IonMonkey compiler. Support for Retina displays on OS X 10.7 and up. Preliminary support for WebRTC. Better image quality with Mozilla's new HTML scaling algorithm. Performance improvements around tab switching. Support for new DOM property window.devicePixelRatio. Improvement in startup time through smart handling of signed extension certificates. Support for W3C touch events implemented, taking the place of MozTouch events. Disable insecure content loading on HTTPS pages. Improved responsiveness for users on proxies. Changes during Aurora releases Adds a Metro user interface on Windows 8.
18.0.1	January 18, 2013	Off-cycle stability update. Fixed problems involving HTTP Proxy Transactions. Fixed unity player crashes on Mac OS X. Disabled HIDPI support on external monitors to avoid rendering glitches.
18.0.2	February 5, 2013	Off-cycle stability update. End-of-life 18.0.x product line on February 19, 2013.
19.0	February 19, 2013	Official Firefox 19.0 release. Built-in PDF Viewer. Canvas elements can export their content as an image blob using canvas.toBlob(). Startup performance improvements. Debugger now supports pausing on exceptions and hiding non-enumerable properties. Remote Web Console is available for connecting to Firefox on Android or Firefox OS (experimental, set devtools.debugger.remote-enabled to true). There is now a Browser Debugger available for add-on and browser developers (experimental, set devtools.chrome.enabled to true). Web Console CSS links now open in the Style Editor. CSS @page is now supported. CSS viewport-percentage length units implemented (vh, vw, vmin and vmax). CSS text-transform now supports full-width. Fixed certain valid WebGL drawing operations that were incorrectly rejected, leaving incomplete rendering in affected pages. Fixed an issue that starting Firefox with -private flag incorrectly claims you are not in Private Browsing mode. Fixed plugins that stop rendering when the top half of the plugin is scrolled off the top of the page, in HiDPI mode.
19.0.1	February 27, 2013	Off-cycle stability update. Windows 8 only: Fixed stability issue for some AMD Radeon HD graphics cards.
19.0.2	March 7, 2013	Off-cycle security update. Released to address a security vulnerability in the HTML editor. Last release for Android 2.1 End-of-life 19.0.x product line on April 2, 2013.
20.0	April 2, 2013	Official Firefox 20.0 release. Per-window Private Browsing. New download experience. Ability to close hanging plugins, without the browser hanging. Continued performance improvements around common browser tasks (page loads, downloads, shutdown, etc.). Continued implementation of draft ECMAScript 6 – clear() and Math.imul. New JavaScript Profiler tool. getUserMedia implemented for web access to the user's camera and microphone (with user permission). <canvas> now supports blend modes. Various <audio> and <video> improvements. Fixed: Details button on Crash Reporter. Fixed: Unity plugin that doesn't display in HiDPI mode.
20.0.1	April 11, 2013	Off-cycle security update. Windows-only update to handle issues around handling UNC paths. End-of-life 20.0.x product line on May 14, 2013.
21.0	May 14, 2013	Official Firefox 21.0 release. The Social API now supports multiple providers. Enhanced three-state UI for Do Not Track (DNT). Preliminary implementation of Firefox Health Report. Firefox will suggest how to improve your application startup time if needed. Ability to Restore removed thumbnails on New tab Page. CSS -moz-user-select:none selection changed to improve compatibility with -webkit-user-select:none. Graphics related performance improvements. Removed E4X support from SpiderMonkey. Implemented Remote Profiling. Integrated, Add-on SDK loader and API libraries into Firefox. Added support for <main> element. Implemented scoped stylesheets. Fixed: Some function keys may not work when pressed. Fixed: Browsing and Download history clearing needs unification to avoid confusion on clearing download history. End-of-life 21.0.x product line on June 25, 2013.
22.0	June 25, 2013	Official Firefox 22.0 release. WebRTC is now enabled by default. Windows: Firefox now follows display scaling options to render text larger on high-res displays. Mac OS X: Download progress in Dock application icon. HTML5 audio/video playback rate can now be changed. Social services management implemented in Add-ons Manager. asm.js optimizations (OdinMonkey) enabled for major performance improvements. Improved WebGL rendering performance through asynchronous canvas updates. Plain text files displayed within Firefox will now word-wrap. For user security, the |Components| object is no longer accessible from web content. Improved memory usage and display time when rendering images. Pointer Lock API can now be used outside of fullscreen. CSS3 Flexbox implemented and enabled by default. New Web Notifications API implemented. Added clipboardData API for JavaScript access to a user's clipboard. New built-in font inspector. New HTML5 <data> and <time> elements Fixed: Scrolling using some high-resolution-scroll aware touchpads feels slow. End-of-life 22.0.x product line on August 6, 2013.
23.0	August 6, 2013	Official Firefox 23.0 release. In this Version Mozilla changed the Firefox Logo. Mixed content blocking enabled to protects users from man-in-the-middle attacks and eavesdroppers on HTTPS pages. Options panel created for Web Developer Toolbox. "Enable JavaScript" preference checkbox has been removed and user-set values will be reset to the default. Improved about:memory's functional UI. Simplified interface for notifications of plugin installation. Enabled DXVA2 on Windows Vista+ to accelerate H.264 video decoding. Users can now switch to a new search provider across the entire browser. CSP policies using the standard syntax and semantics will now be enforced. <input type='file'> rendering improvements. Replaced fixed-ratio audio resampler in webrtc.org capture code with Speex resampler and eliminated pseudo-44,000 Hz rate. "Load images automatically" and "Always show the tab bar" checkboxes removed from preferences and reset to defaults. HTML5 <input type="range"> form control implemented. Write more accessible pages on touch interfaces with new ARIA role for key buttons. Social share functionality. Added unprefixed requestAnimationFrame. Implemented a global browser console. Dropped blink effect from text-decoration: blink; and completely removed <blink> element. New feature in toolbox: Network Monitor.
23.0.1	August 16, 2013	Off-cycle stability update. Fixed rendering glitches on H.264 video only in Firefox 23 on Windows Vista. Fixed spell checking that was broken with non-ASCII characters in profile path. Fixed audio static/"burble"/breakup in Firefox to Firefox WebRTC calls. End-of-life 23.0.x product line on September 17, 2013.

Firefox 24 through 30

Firefox 29 with Australis interface, running on Windows 8.1

Firefox 24 and Firefox 24 ESR were released on September 17, 2013. The release includes support for the new scrollbar style in Mac OS X 10.7 (and newer), closing tabs to the right, an improved browser console for debugging, and improved SVG rendering, among other things. It is the first version of the browser that uses SpiderMonkey 24.

Firefox 25 was released on October 29, 2013. Firefox 25 Nightly was at one point slated to include the Australis theme, but Australis did not actually land on Nightly until Firefox 28, did not make it to Firefox 28 Aurora channel, and was finally available with Firefox 29. This release added support for <iframe srcdoc> attribute, background-attachment:local in CSS, along with Web audio API support, separate find bar for each tab and many other bug fixes.

Firefox 26 was released December 10, 2013. Firefox 26 changed the behavior of Java plugins to "click-to-play" mode instead of automatically running them. It also added support for H.264 on Linux, password manager support for script-generated fields, and the ability for Windows users without advanced write permissions to update Firefox, as well as many bug fixes and developer-related changes.

Firefox 27 was released on February 4, 2014. It adds improved Social API and SPDY 3.1 support, as well as enabling of TLS 1.1 and 1.2 by default. Also, it brings many bug fixes, security improvements, and developer-related changes.

Firefox 28 was released on March 18, 2014. It added support for VP9 video decoding and support for Opus in WebM. For Android, features such as predictive lookup from the address bar, quick share buttons and support for OpenSearch were added.

Firefox 29 was released on April 29, 2014 and includes the Australis interface, it also removes the add-on bar and moves its content to the navigation bar.

Firefox 30 was released on June 10, 2014. It adds support for GStreamer 1.0 and a new sidebar button, and most plugins are not activated by default.

Release history of Firefox 24 – 30
Version	Release date	Release type and highlights
24.0	September 17, 2013	Official Firefox 24.0 release. Support for new scrollbar style in Mac OS X 10.7 and newer. Implemented Close tabs to the right. Social: Ability to tear-off chat windows to view separately by simply dragging them out. Accessibility related improvements on using pinned tabs. Removed support for Revocation Lists feature. Performance improvements on New Tab Page loads. Major SVG rendering improvements around Image tiling and scaling. Improved and unified Browser console for enhanced debugging experience, replacing existing Error console. Removed support for sherlock files that are loaded from application or profile directory. Replaced fixed-ratio audio resampler in webrtc.org capture code with Speex resampler and eliminated pseudo-44,000  rate. End-of-life 24.0.x product line on October 29, 2013.
24.0esr	September 17, 2013	Official Firefox 24.0 Extended Support Release (ESR).
24.1.0esr	October 29, 2013	Regular security update.
24.1.1esr	November 15, 2013	Off-cycle stability update. Updated branches that use 4.10 RTM to 4.10.2 RTM. Updated Mozilla to NSS 3.15.3 (new alternative NSS branch) to pick up a few fixes. Fixed an issue where some UI strings in Firefox 24.1.0 ESR l10n builds are in English.
24.2.0esr	December 10, 2013	Regular security update.
24.3.0esr	February 4, 2014	Regular security update.
24.4.0esr	March 18, 2014	Regular security update.
24.5.0esr	April 29, 2014	Regular security update.
24.6.0esr	June 10, 2014	Regular security update.
24.7.0esr	July 22, 2014	Regular security update.
24.8.0esr	September 2, 2014	Regular security update.
24.8.1esr	September 24, 2014	Off-cycle security update. End-of-life 24.x.x ESR product line on October 14, 2014.
25.0	October 29, 2013	Official Firefox 25.0 release. Web Audio support. The find bar is no longer shared between tabs. If away from Firefox for months, you now will be offered the option to migrate another browser's history and settings. Resetting Firefox no longer clears your browsing session. CSS3 background-attachment:local support to control background scrolling. Many new ES6 functions implemented. iframe document content can now be specified inline. Fixed blank or missing page thumbnails when opening a new tab.
25.0.1	November 15, 2013	Off-cycle security and stability update. Fixed pages that sometimes wouldn't load without first moving the cursor. End-of-life 25.0.x product line on December 10, 2013.
26.0	December 10, 2013	Official Firefox 26.0 release. All Java plug-ins are defaulted to 'click to play'. Password manager now supports script-generated password fields. Updates can now be performed by Windows users without write permissions to Firefox install directory (requires Mozilla Maintenance Service). Support for H.264 on Linux if the appropriate gstreamer plug-ins are installed. Support for MP3 decoding on Windows XP, completing MP3 support across Windows OS versions. CSP implementation now supports multiple policies, including the case of both an enforced and Report-Only policy, per the specification. Social API now supports Social Bookmarking for multiple providers through its SocialMarks functionality. Math.ToFloat32 takes a JavaScript value and converts it to a Float32, whenever possible. There is no longer a prompt when websites use appcache. Support for the CSS image orientation property. New App Manager allows you to deploy and debug HTML5 webapps on Firefox OS phones and the Firefox OS Simulator. IndexedDB can now be used as a "optimistic" storage area so it doesn't require any prompts and data is stored in a pool with LRU eviction policy, in short temporary storage. Fixed: When displaying a standalone image, Firefox matches the Exif orientation information contained within the JPEG image. Fixed: Text Rendering Issues on Windows 7 with Platform Update KB2670838 (MSIE 10 Prerequisite) or on Windows 8.1. Improved page load times due to no longer decoding images that are not visible. Fixed: AudioToolbox MP3 backend for Mac OS X.
26.0.1	December 20, 2013	Off-cycle stability mobile release. Fixed the screen that distorts on some devices after tapping on search suggestion. Fixed: About:home is missing translations in some locales. Most affected are: ca, ga-IE, hu, ko, pt-BR, pt-PT, ro, and uk. Fixed: In some cases, the clip set on the page doesn't update when the addressbar hides. Fixed: Invalid position:fixed rendering. End-of-life 26.0.x product line on February 4, 2014.
27.0	February 4, 2014	Official Firefox 27.0 release. You can now run more than one service at a time with Firefox SocialAPI, allowing you to receive notifications, chat and more from multiple integrated services. Enabled TLS 1.1 (RFC 4346) and TLS 1.2 (RFC 5246) by default. Added support for SPDY 3.1 protocol. Ability to reset style sheets using all:unset. You can now choose to deobfuscate javascript in the debugger. Added support for scrolled fieldsets. Implemented allow-popups directive for iframe sandbox, enabling increased security. CSS cursor keywords -moz-grab and -moz-grabbing have been unprefixed. Added support for ES6 generators in SpiderMonkey. Implemented support for mathematical function Math.hypot() in ES6. Dashed line support on Canvas. Had Azure/Skia content rendering working on Linux.
27.0.1	February 13, 2014	Off-cycle stability release. Fixed stability issues with Greasemonkey and other JavaScript that used ClearTimeoutOrInterval. Fixed: JavaScript math correctness issue. End-of-life 27.0.x product line on March 18, 2014.
28.0	March 18, 2014	Official Firefox 28.0 release. VP9 video decoding implemented. Mac OS X: Notification Center support for web notifications. Volume control for HTML5 audio/video. Support for Opus in WebM. Now that SPDY/3 is implemented support for SPDY/2 has been removed and servers without SPDY/3 will negotiate to HTTP/1 without any penalty. Support for MathML 2.0 'mathvariant' attribute. Background thread hang reporting. Support for multi-line flexbox in layout.
28.0.1	March 24, 2014	Android Off-cycle stability mobile update. Fixed H.264 video playback issues on several Galaxy devices. Fixed mobile-only security fix for file:paths. End-of-life 28.0.x product line on April 29, 2014.
29.0	April 29, 2014	Official Firefox 29.0 release. Significant new customization mode. A new menu sits in the right hand corner of Firefox and includes popular browser controls. New tabs provide an overall smoother look and fade into the background when not active. An interactive onboarding tour to guide users through the new Firefox changes. Added the ability to set up Firefox Sync by creating a Firefox account. Gamepad API finalized and enabled. Malay [ma] locale added. Clicking on a W3C Web Notification will switch to the originating tab. 'box-sizing' (dropping the -moz- prefix) implemented. Console object available in web workers. Promises enabled by default. SharedWorker enabled by default. <input type="number"> implemented and enabled. <input type="color"> implemented and enabled. Enabled ECMAScript Internationalization API. Add-on bar has been removed, content moved to navigation bar. No longer possible to move tabs from the top of the browser without an add-on.
29.0.1	May 9, 2014	Off-cycle stability update. Fixed: An issue with pdf.js printing white pages. Fixed: Tabs not visible with dark themes under Windows 8.1. Fixed: Session Restore failed with a corrupted sessionstore.js file. Fixed: Seer disabled by default. End-of-life 29.0.x product line on June 10, 2014.
30.0	June 10, 2014	Official Firefox 30.0 release. Sidebars button in browser chrome enables faster access to social, bookmark, & history sidebars. Mac OS X command-E sets find term to selected text. Support for GStreamer 1.0. Disallowed calling WebIDL constructors as functions on the web. With the exception of those bundled inside an extension or ones that are whitelisted, plugins will no longer be activated by default. Fixes to box-shadow and other visual overflow. Mute and volume available per window when using WebAudio. Background-blend-mode enabled by default. Use of line-height allowed for <input type="reset|button|submit">. ES6 array and generator comprehensions implemented. Error stack now contains column number. Support for alpha option in canvas context options. Fixed: Ignored autocomplete="off" when offering to save passwords via the password manager. Fixed TypedArrays that don't support new named properties. End-of-life 30.0.x product line on July 22, 2014.

Firefox 31 through 37

Firefox 31 and Firefox 31 ESR were released on July 22, 2014. Both versions added search field on the new tab page and were improved to block malware from downloaded files, along with other new features. Firefox 31 ESR is the first ESR to include the Australis interface, unifying the user experience across different Firefox versions. Firefox 24.x.x ESR versions will be automatically updated to ESR version 31 after October 14, 2014.

Firefox 32 was released on September 2, 2014. It shows off HTTP caching improvements, adds HiDPI/Retina support in the Developer Tools UI and widens HTML5 support, among other things.

Firefox 33 was released on October 14, 2014. It now has off-main-thread compositing (OMTC) enabled by default on Windows (which brings responsiveness improvements), OpenH264 support, search suggestions on about:home and about:newtab, address bar search improvements, session restore reliability improvements, and other changes.

Firefox 33.1 was released on November 10, 2014, celebrating Firefox's 10-year anniversary. Firefox 33.1.1 was released for desktop only on November 14, 2014, fixing a startup crash.

The logo of Firefox Hello.

Firefox 34 was released on December 1, 2014. It brings Firefox Hello (a WebRTC client for voice and video chat), an improved search bar, and the implementation of HTTP/2 (draft14) and ALPN, together with other features. It also disables SSLv3, and enables the ability to recover from a locked Firefox process and to switch themes and personas directly in the customization mode.

Firefox 35 was released on January 13, 2015. It brings support for a room-based conversations model to the Firefox Hello chat service, and other functions, it includes security fixes.

Firefox 36 was released for desktop on February 24, 2015, bringing full HTTP/2 support and other smaller improvements and fixes. It was also released for Android three days later on February 27, 2015, adding support for the tablet user interface.

Firefox 37 was released on March 31, 2015, bringing a heartbeat user rating system, which provides user feedback about the Firefox, and improved protection against website impersonation via OneCRL centralized certificate revocation. Also, Bing search is changed to use HTTPS for secure searching, and added is support for opportunistic encryption of the HTTP traffic where the server supports HTTP/2's AltSvc feature.

Release history of Firefox 31 – 37
Version	Release date	Release type and highlights
31.0	July 22, 2014	Official Firefox 31.0 release. Adds the search field to the new tab page. mozilla::pkix as default certificate verifier. Blocks malware from downloaded files. Partial implementation of the OpenType MATH table. Support of Prefer:Safe http header for parental control. audio/video .ogg and .pdf files handled by Firefox if no application specified (Windows only). Upper Sorbian [hsb] locale added. Removal of the CAPS infrastructure for specifying site-specific permissions (via capability.policy.* preferences). Most notably, attempts to use this functionality to grant access to the clipboard will no longer work. The sole exception is the checkloaduri permission, which may still be used as before to allow sites to load file:// URIs. WebVTT implemented and enabled. CSS3 variables implemented. Developer Tools: Add-on Debugger. Developer Tools: Canvas Debugger. New Array built-in: Array.prototype.fill(). New Object built-in: Object.setPrototypeOf(). CSP 1.1 nonce-source and hash-source enabled by default. Developer Tools: Eyedropper tool added to the color picker. Developer Tools: Editable Box Model. Developer Tools: Code Editor improvements. Developer Tools: Console stack traces. Developer Tools: Copy as cURL. Developer Tools: Styled console logs. navigator.sendBeacon enabled by default. Dialogs spawned from the onbeforeunload event no longer block access to the rest of the browser. Fixed: Search for partially selected link text from context menu. Last release for ARMv7 Android 2.2 End-of-life 31.0.x product line on September 2, 2014.
31.0esr	July 22, 2014	Official Firefox 31.0 Extended Support Release (ESR).
31.1.0esr	September 2, 2014	Regular security update.
31.1.1esr	September 24, 2014	Off-cycle security update.
31.2.0esr	October 14, 2014	Regular security and stability update. Fixed: Invalid certificate issue with mozilla::pkix. Fixed: Importing an RSA private key fails if p < q.
31.3.0esr	December 1, 2014	Regular security and stability update. Fixed: @ JS::Handle::operator JSObject* const&() startup crash. Fixed: Intermittent failures in add-ons manager mochitest-browser tests. Fixed: Bad CPU type in executable running mochitests on Mac OS X Yosemite. Fixed: Error building nsChildView.mm on Mac OS X Yosemite. Fixed: Build error on Mac OS X Yosemite. Fixed: Wrong CPU features detection on some x86 CPUs. Fixed: XMLHttpRequest.send({}) should not throw. Last release for ARMv6 Android
31.4.0esr	January 13, 2015	Regular security update.
31.5.0esr	February 24, 2015	Regular security update.
31.5.2esr	March 20, 2015	Off-cycle security update.
31.5.3esr	March 21, 2015	Off-cycle security update.
31.6.0esr	March 31, 2015	Regular security update.
31.7.0esr	May 12, 2015	Regular security update.
31.8.0esr	July 2, 2015	Regular security update. End-of-life 31.x.x ESR product line on August 11, 2015.
32.0	September 2, 2014	Official Firefox 32.0 release. New HTTP cache provides improved performance including crash recovery. Integration of generational garbage collection. Public key pinning support enabled. Displays the number of found items in the find toolbar. Easier back, forward, reload, and bookmarking through the context menu. Views historical use information for logins stored in password manager. Lower Sorbian [dsb] locale added. Removed and turned off trust bit for some 1024-bit root certificates. Performance improvements to Password Manager and Add-on Manager. drawFocusIfNeeded enabled by default. CSS position:sticky enabled by default. mix-blend-mode enabled by default. Vibration API updated to latest W3C spec. box-decoration-break enabled by default. ECMAScript 6 built-in method Array#copyWithin implemented. New Array built-in: Array.from() navigator.languages property and languagechange event implemented. CSS box-decoration-break replaces -moz-background-inline-policy. HiDPI support in Developer Tools UI. Inspector button moved to the top left. Hidden nodes displayed differently in the markup-view. New Web Audio Editor. Code completion and inline documentation added to Scratchpad. Fixed: Mac OS X: cmd-L does not open a new window when no window is available. Fixed Text Rendering Issues on Windows 7 with Platform Update KB2670838 (MSIE 10 Prerequisite) or on Windows 8.1.
32.0.1	September 10, 2014 (Android) September 12, 2014 (desktop)	Off-cycle stability update. Desktop Fixed stability issues for computers with multiple graphics cards. Fixed mixed content icon that may be incorrectly displayed instead of lock icon for SSL sites. Fixed: WebRTC: setRemoteDescription() silently fails if no success callback is specified. Android Fixed link tap selection that was offset on some Android devices.
32.0.2	September 18, 2014	Desktop Off-cycle stability update. Fixed corrupt installations causing Firefox to crash on update.
32.0.3	September 24, 2014	Off-cycle security update. End-of-life 32.0.x product line on October 14, 2014.
33.0	October 14, 2014	Official Firefox 33.0 release. Windows: OMTC enabled by default. OpenH264 support (sandboxed). Improved search experience through the location bar. Slimmer and faster JavaScript strings. Search suggestions on the Firefox Start (about:home) and new tab (about:newtab) pages. New CSP (Content Security Policy) backend. Support for connecting to HTTP proxy over HTTPS. Improved reliability of the session restoration. Azerbaijani [az] locale added. Proprietary window.crypto properties/functions removed. JSD (JavaScript Debugger Service) removed in favor of the Debugger interface. @counter-style rule from CSS3 Counter Styles specification implemented. DOMMatrix interface implemented. Cubic-bezier curves editor. Displayed which elements have listeners attached. New sidebar which displays a list of shortcuts to every @media rule in the current stylesheet. Paint flashing for browser content repaints. Editable @keyframes rules in the Rules section of the Inspector. CSS transform highlighter in the style-inspector. Fixed incomplete downloads being marked as complete by detecting broken HTTP1.1 transfers.
33.0.1	October 24, 2014	Desktop Off-cycle stability update. Fixed displaying of a black screen at startup with certain graphics drivers.
33.0.2	October 28, 2014	Desktop Off-cycle stability update. Fixed a startup crash with some combination of hardware and drivers.
33.0.3	November 6, 2014	Desktop Off-cycle stability update. Blacklisted graphics drivers that were causing black screens with OMTC enabled. Fixed two startup crashes with some combination of hardware and drivers.
33.1	November 10, 2014	Firefox's 10-year anniversary. Forget button added. Enhanced tiles. Privacy tour introduced. Adding DuckDuckGo as a search option.
33.1.1	November 14, 2014	Desktop Off-cycle stability update. Fixed a startup crash. End-of-life 33.x product line on December 1, 2014.
34.0	December 1, 2014	Official Firefox 34.0 release. Default search engine changed to Yandex for Belarusian, Kazakh, and Russian locales. Improved search bar (en-US only). Firefox Hello real-time communication client. Easily switch themes/personas directly in the Customizing mode. Wikipedia search now uses HTTPS for secure searching (en-US only). Implementation of HTTP/2 (draft14) and ALPN. Recover from a locked Firefox process in the "Firefox is already running" dialog on Windows. Disabled SSLv3. Proprietary window.crypto properties/functions re-enabled (to be removed in Firefox 35). Firefox signed by Apple OS X version 2 signature. ECMAScript 6 WeakSet Implemented. JavaScript Template Strings Implemented. CSS3 Font variants and features control (e.g. kerning) implemented. WebCrypto: RSA-OAEP, PBKDF2, ECDH, and AES-KW support. wrapKey and unwrapKey implemented. Import/export of JWK-formatted keys. matches() DOM API implemented (formerly mozMatchesSelector()). Performance.now() for workers implemented. WebIDE: Create, edit, and test a new Web application from your browser. Highlight all nodes that match a given selector in the Style Editor and the Inspector's Rules panel. Improved User Interface of the Profiler. console.table function added to web console. Fixed: CSS transitions start correctly when started at the same time as changes to display, position, overflow, and similar properties.
34.0.5	December 1, 2014	Desktop Official Firefox 34.0.5 release. Default search engine changed to Yahoo! for North America. End-of-life 34.0.x product line on January 13, 2015.
35.0	January 13, 2015	Official Firefox 35.0 release. Firefox Hello with new rooms-based conversations model. New search UI improved and enabled for more locales. Access the Firefox Marketplace from the Tools menu and optional toolbar button. Built-in support for H264 (MP4) on Mac OS X Snow Leopard (10.6) and newer through native APIs. Use of tiled rendering on Mac OS X. Improved high quality image resizing performance. Improved handling of dynamic styling changes to increase responsiveness. Implemented HTTP Public Key Pinning Extension (for enhanced authentication of encrypted connections). Added support for the CSS Font Loading API. Resource Timing API implemented. CSS filters enabled by default. Changed JavaScript 'let' semantics to match the ES6 specification. Support for inspecting ::before and ::after pseudo elements. Computed view: Nodes matching the hovered selector are now highlighted. Network Monitor: New request/response headers view. Added support for the EXT_blend_minmax WebGL extension. Fixed: Show DOM Properties context menu item in inspector. Reduced resource usage for scaled images. PDF.js updated to version 1.0.907. Non-HTTP(S) XHR now returns correct status code. Changes during Developer Edition releases Renamed to Firefox Developer Edition for alpha "Aurora" releases since November 10, 2014.
35.0.1	January 26, 2015 (desktop) February 5, 2015 (Android)	Off-cycle stability update. Fixed a crash with the Enhanced Steam extension. Fixed a potential startup crash. Fixed Kerberos authentication failure with alias. Fixed SVG / CSS animation regression causing rendering issues on websites like openstreetmap.org. Fixed a crash on Godaddy webmail. Fixed an update failure of document.baseURI to document.location after base tag was removed from DOM for site with a CSP. Fixed a text selection broken with a Right-to-left (RTL) version of Firefox. CSP had a change in behavior with regard to case sensitivity resources loading. Android Fixed crash with video playback on Asus MeMO Pad 10 and 8, Tesco Hudl, Lenovo Lifetab E models, and several other devices running the Rockchip SoC. End-of-life 35.0.x product line on February 24, 2015.
36.0	February 24, 2015 (desktop) February 27, 2015 (Android)	Official Firefox 36.0 release. Pinned tiles on the new tab page can be synced. Added full support for HTTP/2. Locale added: Uzbek (UZ). Remote option removed. No longer accepting insecure RC4 ciphers whenever possible. Phasing out Certificates with 1024-bit RSA Keys. Shut down hangs will now show the crash reporter before exiting the program. Add-on compatibility changed. Support for the ECMAScript 6 Symbol data type added. Unicode-range CSS descriptor implemented. CSSOM-View scroll behavior implemented allowing smooth scrolling of content without custom libraries. Object-fit and object-position implemented. Isolation CSS property implemented. CSS3 will-change property implemented. Changed JavaScript 'const' semantics to conform better to the ES6 specification. Improved ES6 generators for better performance. Eval sources now appear in the Debugger. DOM Promises inspection. Inspector: More paste options in markup view. CSS gradients work on premultiplied colors. Fixed some unexpected logout from Facebook or Google after restart.
36.0.1	March 5, 2015 (desktop) March 6, 2015 (Android)	Off-cycle stability update. Disabled the usage of the ANY DNS query type. Fixed a startup crash with EMET. Fixed the Hello contact that may become inactive until restart. Fixed print preferences that may not be preserved. Fixed Hello contact tabs that may not be visible. Accepted hostnames that include an underscore character _. Fixed the WebGL that may use significant memory with Canvas2d. Option -remote has been restored. Fixed a top crash.
36.0.2	March 16, 2015	Android Off-cycle stability mobile update. Fixed a startup crash on HTC One M8 devices (Verizon) with Android 5.0.1. Fixed some potential crashes with Flash videos.
36.0.3	March 20, 2015	Off-cycle security update. Security fix for an issue disclosed at HP Zero Day Initiative's Pwn2Own contest.
36.0.4	March 21, 2015	Off-cycle security update. Security fix for an issue disclosed at HP Zero Day Initiative's Pwn2Own contest. End-of-life 36.0.x product line on March 31, 2015.
37.0	March 31, 2015	Official Firefox 37.0 release. Heartbeat user rating system – your feedback about Firefox. Yandex set as default search provider for the Turkish locale. Bing search now uses HTTPS for secure searching. Improved protection against site impersonation via OneCRL centralized certificate revocation. Opportunistically encrypts HTTP traffic where the server supports HTTP/2 AltSvc. Disabled insecure TLS version fallback for site security. Extended SSL error reporting for reporting non-certificate errors. TLS False Start optimization now requires a cipher suite using AEAD construction. Improved certificate and TLS communication security by removing support for DSA. Improved performance of WebGL rendering on Windows. Implemented a subset of the Media Source Extensions (MSE) API to allow native HTML5 playback on YouTube. Added support for CSS display:contents. IndexedDB now accessible from worker threads. New SDP/JSEP implementation in WebRTC. Debug tabs opened in Chrome Desktop, Chrome for Android, and Safari for iOS. New Inspector animations panel to control element animations. New Security Panel included in Network Panel. Debugger panel support for chrome:// and about:// URIs. Added logging of weak ciphers to the web console.
37.0.1	April 3, 2015	Off-cycle stability and security update. Disabled HTTP/2 AltSvc introduced in 37.0 due to security issues. Desktop Fixed start-up crash due to graphics hardware and third party software. Android Fixed crash due to WebRTC usage on certain web sites.
37.0.2	April 14, 2015 (Android) April 20, 2015 (desktop)	Off-cycle stability and security update. Desktop Fixed an issue with Google Maps rendering incorrectly in some cases. Fixed stability issues for some graphics hardware and feature sets. Security fixes. Android Fixed an issue related to the "request desktop site" feature. End-of-life 37.0.x product line on May 12, 2015.

Firefox 38 through 44

Both Firefox 38 and Firefox 38 ESR were released on May 12, 2015, with new tab-based preferences, Ruby annotation support and availability of WebSockets in web workers, along with the implementation of the BroadcastChannel API and other features and security fixes.

Firefox 39 was released on July 2, 2015 for desktop and Android, disabling insecure SSLv3 and RC4, improving performance for IPv6 fallback to IPv4 and including various security fixes. Firefox 39.0.3 was released on August 6, 2015, to fix a zero-day exploit.

Firefox 40 was released on August 11, 2015 for desktop and Android. On Windows 10, the Australis theme was updated to reflect the overall appearance of Windows 10, and the interface is adapted for usability on touchscreens when used in the operating system's "Tablet mode". Firefox 40 includes additional security features, including the filtering of pages that offer potentially unwanted programs, and warnings during the installation of unsigned extensions; in future versions, signing of extensions will become mandatory, and the browser will refuse to install extensions that have not been signed. Firefox 40 also includes performance improvements, such as off-main-thread compositing on Linux.

Firefox 41 was released on September 22, 2015 for desktop and Android. Among many additions are the ability to set a profile picture for a Firefox account, enhanced IME support using Text Services Framework, and instant messaging on Firefox Hello.

Firefox 42 was released on November 3, 2015 for desktop and Android. Among many additions are private browsing with tracking protection, IPv6 support in WebRTC, and the ability to view HTML source in a tab.

Firefox 43 was released on December 15, 2015 for desktop and Android. Among many additions are the availability of the 64-bit version for Windows 7 and above, a new strict blocklist, and audio indicators on Android.

Firefox 44 was released on January 26, 2016 for desktop and Android. Among many additions are the improvement of warning pages for certificate errors and untrusted connections, enabling of H.264 and WebM/VP9 video support on systems that don't support MP4/H.264, support for the brotli compression format via HTTPS content-encoding, and the use of Android print service to enable cloud printing. "Ask me every time" cookies option was removed without any notifications.

Release history of Firefox 38 – 44
Version	Release date	Release type and highlights
38.0	May 12, 2015	Official Firefox 38.0 release. New tab-based preferences. Ruby annotation support. Base for the next ESR release. autocomplete=off is no longer supported for username/password fields. URL parser avoids doing percent encoding when setting the Fragment part of the URL, and percent decoding when getting the Fragment in line with the URL spec. RegExp.prototype.source now returns "(?:)" instead of the empty string for empty regular expressions. Improved page load times via speculative connection warmup. WebSocket now available in web workers. BroadcastChannel API implemented. Implemented srcset attribute and <picture> element for responsive images. Implemented DOM3 Events KeyboardEvent.code. Mac OS X: Implemented a subset of the Media Source Extensions (MSE) API to allow native HTML5 playback on YouTube. Implemented Encrypted Media Extensions (EME) API to support encrypted HTML5 video/audio playback (Windows Vista or later only). Automatically downloaded Adobe Primetime Content Decryption Module (CDM) for DRM playback through EME (Windows Vista or later only). Optimized-out variables are now visible in Debugger UI. XMLHttpRequest logs in the web console are now visually labelled and can be filtered separately from regular network requests. WebRTC now has multistream and renegotiation support. copy command added to console.
38.0esr	May 12, 2015	Official Firefox 38.0 Extended Support Release (ESR).
38.0.1	May 14, 2015 (desktop) May 15, 2015 (Android)	Off-cycle stability update. Desktop Fixed a crash on start-up with first generation NVidia Optimus graphics cards. Fixed a problem in which users who import cookies from Google Chrome can end up with broken websites. Fixed a problem that large animated images may fail to play and may stop other images from loading. Fixed a problem that WebRTC H264 video streams from CiscoSpark native clients are not decoded correctly (Fixed in Firefox ESR 38.0.1; was already fixed in Firefox 38.0). Android Fixed a crash on start-up on devices for which Firefox does not support Android hardware acceleration. Fixed a problem that large animated images may fail to play and may stop other images from loading. Fixed a problem that Mozilla Location Service (MLS) stumbler may not submit all data.
38.0.1esr	May 14, 2015	Off-cycle stability update.
38.0.5	June 2, 2015	Official Firefox 38.0.5 release. Desktop Integration of Pocket. Implementation of Reader View. Share the active tab or window in a Hello conversation. Fixed a problem that would cause Firefox to stop painting when switching tabs. Fixed graphics performance when using the built-in VGA driver on Windows 7. Android Integrated Adjust SDK to measure aggregate installs. Fixed various stability fixes. End-of-life 38.0.x product line on July 2, 2015.
38.0.6	June 9, 2015	;Desktop Off-cycle update. Fixes bugs in Firefox 38.0.5 funnelcake builds. Note: This release is only available from the Mozilla archives. End-of-life 38.0.x product line on July 2, 2015.
38.1.0esr	July 2, 2015	Regular security update.
38.1.1esr	August 6, 2015	Off-cycle security update. Patches zero-day exploit.
38.2.0esr	August 11, 2015	Regular security and stability update. Fixed: Firefox may become unresponsive after right-clicking Flash content on Windows 8. Fixed: Firefox may crash during mp4 video playback. Fixed branded Firefox application that does not open URLs in system default browser. Fixed significant memory leak with GreaseMonkey add-on. Fixed crash [@ RtlEnterCriticalSection | MessageLoop::PostTask_Helper] on browser shutdown. Fixed browser UI that becomes unresponsive state when using Unity Web Player Plugin. Fixed ESRs that would not build on hppa platform. Fixed crash in mozilla::layers::SyncObjectD3D11::FinalizeFrame().
38.2.1esr	August 27, 2015	Off-cycle security update.
38.3.0esr	September 22, 2015	Regular security update.
38.4.0esr	November 3, 2015	Regular security update.
38.5.0esr	December 15, 2015	Regular security update. Improved stability with Java.
38.5.1esr	December 21, 2015	Off-cycle stability update. Preparing to use SHA-256 signing certificate for Windows builds, to meet new signing requirement.
38.5.2esr	December 22, 2015	Off-cycle security and stability update. Use of a SHA-256 signing certificate for Windows builds, to meet new signing requirements.
38.6.0esr	January 26, 2016	Regular security update.
38.6.1esr	February 11, 2016	Off-cycle graphite2 library update. Updated graphite2 library to latest release.
38.7.0esr	March 8, 2016	Regular security update.
38.7.1esr	March 16, 2016	Off-cycle stability update. Fixed an issue in which loading from history can show the wrong url in the location bar. Disabled Graphite font shaping library.
38.8.0esr	April 26, 2016	Regular security update. End-of-life 38.x.x ESR product line on June 7, 2016.
39.0	July 2, 2015	Official Firefox 39.0 release. Share Hello URLs with social networks. Project Silk for Mac OS X: Smoother animation and scrolling. Support for 'switch' role in ARIA 1.1 (web accessibility). SafeBrowsing malware detection lookups enabled for downloads on Mac OS X and Linux. Support for new Unicode 8.0 skin tone emoji. Removed support for insecure SSLv3 for network communications. Disable use of RC4 except for temporarily whitelisted hosts. The malware detection service for downloads now covers common Mac file types. Performance of displaying dashed lines is improved on Mac OS X. List-style-type now accepts a string value. Enable the Fetch API for network requests from dedicated, shared and service workers. Cascading of CSS transitions and animations now matches the current spec. Implement <link rel="preconnect">allowing anticipation of a future connection without revealing any information. Added support for CSS Scroll Snap Points. Drag and drop enabled for nodes in Inspector markup view. Webconsole input history persists even after closing the toolbox. Cubic bezier tooltip now shows a gallery of timing-function presets for use with CSS animations. localhost is now available offline for WebSocket connections. Improve performance for IPv6 fallback to IPv4. Fixed incomplete downloads being marked as complete by detecting broken HTTP1.1 transfers. Fixed the security state indicator on a page now correctly ignores loads caused by previous pages. Fixed an issue where a Hello conversation window would sometimes fail to open. Fixed a regression that could lead to Flash not displaying has been fixed. Update to NSS 3.19.2.
39.0.3	August 6, 2015	Off-cycle security update. Patches zero-day exploit. End-of-life 39.0.x product line on August 11, 2015.
40.0	August 11, 2015	Official Firefox 40.0 release. Support for Windows 10. Added protection against unwanted software downloads. User can receive suggested tiles in the new tab page based on categories Firefox matches to browsing history (en-US only). Hello allows adding a link to conversations to provide context on what the conversation will be about. New style for add-on manager based on the in-content preferences style. Improved scrolling, graphics, and video playback performance with off-main-thread compositing (Linux only). Graphic blocklist mechanism improved: Firefox version ranges can be specified, limiting the number of devices blocked. Add-on extensions that are not signed by Mozilla will display a warning. NPAPI Plug-in performance improved via asynchronous initialization. Smoother animation and scrolling with hardware vsync (Windows only). JPEG images use less memory when scaled and can be painted faster. Sub-resources can no longer request HTTP authentication, thus protecting users from inadvertently disclosing login data. IndexedDB transactions are now non-durable by default. Implemented AudioBufferSourceNode.detune to modulate playback rate in cents, a logarithmic unit of measure used for musical intervals. Improved Performance tools in the developer tools: Waterfall view, Call Tree view and a Flame Chart view. New rules view tooltip in the Inspector to tweak CSS Filter values. Console API messages from SharedWorker and ServiceWorker are now displayed in web console. New page ruler highlighting tool that displays lightweight horizontal and vertical rules on a page. Inspector now searches across all content frames in a page. Fixed Kannada text that does not display properly in built-in pdf viewer.
40.0.2	August 13, 2015	Desktop Off-cycle stability update. Enabled API allowing Windows 10 users to open settings dialog. Fixed mozalloc.lib that was missing from the xulrunner package. Fixed a startup crash with some combination of hardware and drivers.
40.0.3	August 27, 2015	Off-cycle stability and security update. Disabled the asynchronous plugin initialization. Fixed a segmentation fault in the GStreamer support (Linux only). Fixed a startup crash when using DisplayLink (Windows only). Fixed a regression with some Japanese fonts used in the <input> field. Fixed an issue that the selection in a select combox box using the mouse could be broken on some sites. Fixed an issue that some search partner codes were missing. End-of-life 40.0.x product line on September 22, 2015.
41.0	September 22, 2015	Official Firefox 41.0 release. Enhanced IME support on Windows (Vista +) using TSF (Text Services Framework). Ability to set a profile picture for your Firefox Account. Firefox Hello now includes instant messaging. SVG images can be used as favicons. Improved box-shadow rendering performance. WebRTC now requires perfect forward secrecy. WARP is disabled on Windows 7. Updates to image decoding process. Support for running animations of 'transform' and 'opacity' on the compositor thread. MessageChannel and MessagePort API enabled by default. Added support for the transform-origin property on SVG elements. CSS Font Loading API enabled by default. Navigator.onLine now varies with actual internet connectivity (Windows and Mac OS X only). Copy/Cut Web content from JavaScript to the OS clipboard with document.execCommand("cut"/"copy"). Implemented Cache API for querying named caches that are accessible Window, Worker, and ServiceWorker. Removed support for binary XPCOM components in extensions, use addon SDK "system/child_process" pipe mechanism for native binaries instead. Network requests can be exported in HAR format. Quickly adds new CSS rule with New Rule button in the Inspector. Screenshots a node or element from markup view with the Screenshot Node context menu item. Copies element CSS rule declarations with the Copy Rule Declaration context menu item in the Inspector. Pseudo-Class panel in the Inspector. Fixed an issue where picture element does not react to resize/viewport changes.
41.0.1	September 30, 2015	Desktop Off-cycle stability update. Fixed a startup crash related to Yandex toolbar and Adblock Plus. Fixed potential hangs with Flash plugins. Fixed a regression in the bookmark creation. Fixed a startup crash with some Intel Media Accelerator 3150 graphic cards. Fixed a graphic crash, occurring occasionally on Facebook.
41.0.2	October 15, 2015	Off-cycle security update. End-of-life 41.0.x product line on November 3, 2015.
42.0	November 3, 2015	Official Firefox 42.0 release. Private Browsing with Tracking Protection that blocks certain Web elements that could be used to record your behavior across sites. Control Center that contains site security and privacy controls. Indicator added to tabs that play audio with one-click muting. WebRTC improvements: IPV6 support. Preferences for controlling ICE candidate generation and IP exposure. Hooks for extensions to allow/deny createOffer/Answer. Improved ability for applications to monitor and control which devices are used in getUserMedia. Login Manager improvements: Improved heuristics to save usernames and passwords. Editing and showing all logins in line, Copy/Paste usernames/passwords from the Context menu. Migration imports your passwords to Firefox from Google Chrome for Windows and Internet Explorer; import anytime from the Login Manager. Improved performance on interactive websites that trigger a lot of restyles. Implemented ES6 Reflect. Support for ImageBitmap and createImageBitmap(). Media Source Extension for HTML5 video available for all sites. Viewing HTML source in a tab. Remote website debugging over WiFi (no USB cable or ADB needed). Asynchronous call stacks now allow web developers to follow the code flow through setTimeout, DOM event handlers, and Promise handlers. Configurable Firefox OS Simulator in WebIDE, to simulate reference devices like phones, tablets, even TVs. CSS filter presets in the Inspector. Ability to save filter presets inside CSS Filter Tooltip. End-of-life 42.0.x product line on December 15, 2015.
43.0	December 15, 2015	Official Firefox 43.0 release. Private Browsing with Tracking Protection offers choice of blocking additional trackers. Improved API support for m4v video playback. Firefox 64-bit for Windows is now available via the Firefox download page. Users can choose search suggestions from the Awesome Bar. On-screen keyboard displayed on selecting input field on devices running Windows 8 or greater. Firefox Health Report has switched to use the same data collection mechanism as telemetry. Markup view shows indicators for pseudo-classes locked for elements. Binding F1 key to open the settings when the toolbox is focused. New 'Use in Console' context menu item in Inspector to store selected element in a temporary variable. Search button next to overridden CSS properties to find similar properties in the rules view. Ability to filter styles from their property names in the rules view. Stack traces are now shown for exceptions inside the console. Added ability to display server-side logs in the console. Ability to choose resolution for the GCLI screenshot command. Subresource integrity allows developers to make their sites more secure. Network requests in Console now link to Network panel instead of opening in a popup. Unprefixed 'hyphens' property is now supported. WebIDE now has a sidebar-based UI. The 'transform-origin' property is now supported on SVG elements. Animation inspector now displays animations in a timeline. Single-process mode is no longer supported for NPAPI plugins. Fixed an issue in which the Eyedropper tool does not work as expected when page is zoomed. Various security fixes.
43.0.1	December 18, 2015	Desktop Off-cycle stability update. Preparing to use SHA-256 signing certificate for Windows builds, to meet new signing requirement.
43.0.2	December 22, 2015	Desktop Off-cycle security and stability update. Use of a SHA-256 signing certificate for Windows builds, to meet new signing requirements.
43.0.3	December 28, 2015	Desktop Off-cycle stability update. Fixed network issue when using Nvidia's Network Access Manager. Improved the decoding of some videos on YouTube on some Windows configurations.
43.0.4	January 6, 2016	Desktop Off-cycle stability update. Fix for startup crash for users of a third party antivirus tool. Multi-user GNU/Linux download folders can be created. Re-enabled SHA-1 certificates. The last version to support HTTP cookie prompts. End-of-life 43.0.x product line on January 26, 2016.
44.0	January 26, 2016	Official Firefox 44.0 release. Improved warning pages for certificate errors and untrusted connections. Enabled H.264 if system decoder is available. Enabled WebM/VP9 video support on systems that don't support MP4/H.264. In the animation-inspector timeline, lightning bolt icon next to animations running on the compositor thread. Support for the brotli compression format via HTTPS content-encoding. Screenshot commands allow user choice of pixel ratio in Developer Tools. Fixed an issue where Windows XP and Vista screensaver doesn't disable when watching videos. Various security fixes. To support unicode-range descriptor for webfonts, font matching under Linux now uses the same font matching code as other platforms. Use of a SHA-256 signing certificate for Windows builds, to meet new signing requirements. Firefox has removed support for the RC4 decipher. Firefox will no longer trust the Equifax Secure Certificate Authority 1024-bit root certificate or the UTN – DATACorp SGC to validate secure website certificates. Stricter validation of web fonts. On-screen keyboard support temporarily turned off for Windows 8 and Windows 8.1. Right-clicking on a logged object in the console to store it as a global variable on the page. Visual tools for Animation:. View/Edit CSS animation keyframe rules directly in the inspector. Visually modify the cubic-bezier curve that drives the way animations progress through time. Discover and scrub through all CSS animations and transitions playing on the page. Learn more: http://devtoolschallenger.com/. Visual tools for Layout and Styles: Display rulers along the viewport to verify size and position and use the measurement tool to easily detect spacing and alignment problems. Use CSS filters to preview and create real-time effects like drop-shadows, sepia, etc.. Learn more: http://devtoolschallenger.com/. New memory tool for inspecting the memory heap. Service Workers API. Built-in JSON reader to intuitively view, search, copy and save data without extensions. A jump to function definitions in the debugger with Cmd-Click. WebSocket Debugging API and add-on. The rule view now displays styles using their authored text, and edits in the rule view are now linked to the style editor. Changes during Nightly releases This and newer versions erase the cookie permissions database of any previous Firefox version.
44.0.1	February 8, 2016	Desktop Off-cycle stability update. Fixed an issue which could lead to the removal of stored passwords under certain circumstances. Allows spaces in cookie names. Requires NSS 3.21. Fixed a crash in cache networking. Fix for using WebSockets in service worker controlled pages. Disabled opus/vorbis audio with H.264. Shipment for the Gecko SDK. Fix for graphics startup crash on GNU/Linux.
44.0.2	February 11, 2016	Off-cycle security and stability update. Fixed an issue where Firefox hangs or crashes on startup. End-of-life 44.0.x product line on March 8, 2016.

Firefox 45 through 51

Firefox 45 and Firefox 45 ESR were released on March 8, 2016 for desktop (both) and Android (no ESR). Among many additions were Instant Browser sharing through Hello, the addition of Guarani locale, the ability to filter snapshot output in memory tool, and the removal of Tab Groups (panorama) feature.

Firefox 46 was released on April 26, 2016 for both desktop and Android. Among the many additions were improved security of the JavaScript Just In Time (JIT) Compiler, the GTK3 integration (Linux only), HKDF support for Web Crypto API, and removal of support for Android 3.0 (Android only).

Firefox 47 was released on June 7, 2016 for both desktop and Android. Among the many additions were support for Google’s Widevine CDM on Windows and Mac OS X so streaming services like Amazon Video can switch from Silverlight to encrypted HTML5 video; enabling VP9 video codec for users with fast machines; the ability of embedded YouTube videos to play with HTML5 video if Flash is not installed; and the addition of the Latgalian language. It is also the last Firefox version to support Android 2.3.x.

Firefox 48 was released on August 2, 2016 for both desktop and Android. Among the many additions were enhanced download protection and the removal of Windows Remote Access Service modem Autodial. It was also the first official release with "Electrolysis" (multi-process Firefox, meaning that the interface and web pages are running in separate processes in the computer) was enabled for part of the users.

Firefox 48 is the last Firefox version to support Mac OS X Snow Leopard, Mac OS X Lion, and OS X Mountain Lion. Additionally, support for old processors without SSE2 extensions such as the AMD Athlon XP and Pentium III was dropped.

Firefox 49 was released on September 20, 2016 for both desktop and Android. Among the many additions were an updated Firefox Login Manager, improved video performance for users on systems that support SSE3 without hardware acceleration, added context menu controls to HTML5 audio and video that let users loop files or play files at 1.25x speed, improvements in about:memory reports for tracking font memory usage, and the removal of Firefox Hello. The macOS version now requires at least OS X Mavericks, and the Microsoft Windows version requires a CPU which supports SSE2.

Firefox 50 was released on November 15, 2016 for both desktop and Android. Among the many additions were playback video on more sites without plugins with WebM EME Support for Widevine on Windows and Mac, improved performance for SDK extensions or extensions using the SDK module loader; download protection for a large number of executable file types on Windows, macOS, and Linux, increased availability of WebGL to more than 98 percent of users on Windows 7 and newer (desktop), and support for HLS videos via player overlay (Android).

Firefox 51 was released on January 24, 2017 for both desktop and Android. Among the many additions were added support for FLAC (Free Lossless Audio Codec) playback, better Tab Switching, support for WebGL 2, and a warning that is displayed when a login page does not have a secure connection.

Release history of Firefox 45 – 51
Version	Release date	Release type and highlights
45.0	March 8, 2016	Official Firefox 45.0 release. Instant browser tab sharing through Hello. Tabs synced via Firefox Accounts from other devices are now shown in dropdown area of Awesome Bar when searching. Synced Tabs button in button bar. Introduces a new preference (network.dns.blockDotOnion) to allow blocking .onion at the DNS level. Guarani [gn] locale added. URLs containing a Unicode-format Internationalized Domain Name (IDN) are now properly redirected. Various security fixes. Tab Groups (Panorama) feature removed. Ability to filter snapshot output in memory tool. Fine-tuning animations by changing the playback rate of animations in the animation-inspector's timeline. DOMContentLoaded and load events shown in the network monitor timeline. Added Negative url filtering for the network monitor. Support for diffing heap snapshots added to the memory tool. Inspector search now matches results from all content in the page, including subframes. List of animated properties and keyframes is now displayed when clicking on an animation in the animation-inspector’s timeline. Push API support, part of Progressive Web Applications. Support for delivery of a Content Security Policy (CSP) via a meta tag. Web Speech synthesis API. ES6 Classes.
45.0.1	March 16, 2016	Off-cycle stability update. Fix for a potential performance regression (YouTube for example). Fix for a regression causing search engine settings to be lost in some context. Brings back non-standard jar: URIs to fix a regression in IBM iNotes. Fixed an issue in which XSLTProcessor.importStylesheet was failing when <import> was used. Fix for an issue which could cause the list of search provider to be empty. Fix for a regression when using the location bar. Fix for some loading issues when Accept third-party cookies: was set to Never. Disabled Graphite font shaping library.
45.0.2	April 11, 2016	Off-cycle stability update. Fix for an issue impacting the cookie header when third-party cookies are blocked. Fix for a web compatibility regression impacting the srcset attribute of the image tag. Fix for a crash impacting the video playback with Media Source Extension. Fix for a regression impacting some specific uploads. Desktop Fix for a regression with the copy and paste with some old versions of some Gecko applications like Thunderbird. Android Last release for Android 3.0 End-of-life 45.0.x product line on April 26, 2016.
45.0esr	March 8, 2016	Official Firefox 45.0 Extended Support Release (ESR).
45.0.1esr	March 16, 2016	Off-cycle stability update. Same changelog of 45.0.1
45.0.2esr	April 11, 2016	Off-cycle stability update. Same changelog of 45.0.2
45.1.0esr	April 26, 2016	Regular security and stability update.
45.1.1esr	May 3, 2016	Off-cycle stability update. Fixed a build issue when jit is disabled. Fixed add-on signing certificate expiration. Fixed a graphics-related shutdown crash.
45.2.0esr	June 7, 2016	Regular security and stability update. Fixed graphics-related crashes. Fixed unicode support for AutoConfig API. Web compatibility fix for addEventListener API.
45.3.0esr	August 2, 2016	Regular security and stability update.
45.4.0esr	September 20, 2016	Regular security update.
45.5.0esr	November 15, 2016	Regular security update.
45.5.1esr	November 30, 2016	Off-cycle security update.
45.6.0esr	December 13, 2016	Regular security update.
45.7.0esr	January 24, 2017	Regular security update.
45.8.0esr	March 7, 2017	Regular security update.
45.9.0esr	April 19, 2017	Regular security update. End-of-life 45.x.x ESR product line on June 13, 2017.
46.0	April 26, 2016	Official Firefox 46.0 release. Improved security of the JavaScript Just In Time (JIT) Compiler GTK3 integration (GNU/Linux only) Screen reader behavior with blank spaces in Google Docs corrected Corrected rendering for scaled SVGs that use a clip and a mask WebRTC fixes to improve performance and stability Display of dominator trees in Memory tool Allocation and garbage collection pause profiling in the performance panel Launch of responsive mode from the Style Editor @media sidebar Added support for document.elementsFromPoint Added HKDF support for Web Crypto API
46.0.1	May 3, 2016	Off-cycle stability update. Fixed add-on signing certificate expiration. Fixed service worker update issue. Fixed a build issue when jit is disabled. Fixed a page loading issue related to antivirus software. Searched a plugin issue for various locales. Limited Sync registration updates. End-of-life 46.0.x product line on June 7, 2016.
47.0	June 7, 2016	Official Firefox 47.0 release. Support for Google’s Widevine CDM on Windows and Mac OS X so streaming services like Amazon Video can switch from Silverlight to encrypted HTML5 video. Enabled VP9 video codec for users with fast machines Embedded YouTube videos now play with HTML5 video if Flash is not installed. Ability to view and search open tabs from your smartphone or another computer in a sidebar Allowed no-cache on back/forward navigations for https resources Latgalu [ltg] locale added. Various security fixes FUEL (Firefox User Extension Library) has been removed. Add-ons relying on it will stop working. The browser.sessionstore.restore_on_demand preference has been reset to its default value (true) to avoid e10s performance problems. The Firefox click-to-activate plugin whitelist has been removed. Web platform changes Ability to view, start, and debug registered Service Workers in the Service Workers developer tool Ability to simulate Push messages in the Service Workers developer tool 'Start' button for service workers in about:debugging to start registered Service Workers Changes that can affect add-on compatibility Added support for ChaCha20/Poly1305 cipher suites Custom user agents supported in Responsive Design Mode Smart multi-line input in the Web Console cuechange events are now available on TextTrack objects WebCrypto: PBKDF2 supports SHA-2 hash algorithms WebCrypto: RSA-PSS signature support Android Last release to support Android 2.3.x (Gingerbread)
47.0.1	June 28, 2016	Desktop Off-cycle stability update. Fixed an issue in which Selenium WebDriver may cause Firefox to crash at startup.
47.0.2	November 1, 2016	Off-cycle stability update. Detect SSE hardware version. Detect Websense to protect users from a startup crash. End-of-life 47.0.x product line on November 1, 2016.
48.0	August 2, 2016	Official Firefox 48.0 release. Roar for moar protection against harmful downloads! We've got your back. Process separation (e10s) is enabled for some of you. Like it? Let us know and we'll roll it out to more. Add-ons that have not been verified and signed by Mozilla will not load. GNU/Linux fans: Get better Canvas performance with speedy Skia support. Try saying that three times fast. WebRTC embetterments: Delay-agnostic AEC enabled. Full duplex for GNU/Linux enabled. ICE Restart & Update is supported. Cloning of MediaStream and MediaStreamTrack is now supported. Searching for something already in your bookmarks or open tabs? We added super smart icons to let you know. Tab (move buttons) and Shift+F10 (pop-up menus) now behave as they should in Firefox customization mode (Windows only). The media parser has been redeveloped using the Rust programming language. Heyo, Jabra & Logitech C920 webcam users. Fixed WebRTC bugs causing frequency distortions. Improved step debugging on last line of functions. After version 48, SSE2 CPU extensions are going to be required on Windows. Au revoir to Windows Remote Access Service modem Autodial. WebExtensions support is now considered as stable. Want to move absolute & fixed positioned elements? Now you can with our geometry editor. The memory tool now has a tree map view for your debugging pleasure. We're putting the spotlight on the background. Now you can debug WebExtensions background content scripts and background pages. Content Security Policy (CSP) is now enforced for WebExtensions. Old and busted: Error Console. New hotness: Browser Console for your debugging pleasure. Add-on development just got easier because you can reload them from about:debugging — because we're all about debugging. This theme is hot, hot, hot! Say hi to the Firebug theme for Developer Tools. Expanded network requests from the console panel to view request details in line, so you can see things in context. Workers can now use the Web Crypto API.
48.0.1	August 18, 2016	Desktop Off-cycle stability update. Fix for an audio regression impacting some major websites. Fix for a top crash in the JavaScript engine. Fix for a startup crash issue caused by Websense. Fix for a different behavior with e10s / non-e10s on <select> and mouse events. Fix for a top crash caused by plugin issues. Fix for an unsigned add-ons issue on Windows. Fix for a shutdown issue. Fix for a crash in WebRTC.
48.0.2	August 24, 2016	Desktop Off-cycle stability update. Fix for a startup crash issue caused by Websense (Windows only). Last release for Mac OS X 10.6-10.8. End-of-life 48.0.x product line on September 20, 2016.
49.0	September 20, 2016	Official Firefox 49.0 release. Updated Firefox Login Manager to allow HTTPS pages to use saved HTTP logins. It’s one more way Firefox is supporting Let’s Encrypt and helping users transition to a more secure web. Added features to Reader Mode that make it easier on the eyes and the ears. Controls that allow users to adjust the width and line spacing of text. Narrate, which reads the content of a page out loud. Improved video performance for users on systems that support SSSE3 without hardware acceleration. Added context menu controls to HTML5 audio and video that let users loops files or play files at 1.25x speed. Improved performance on OS X systems without hardware acceleration. Improved appearance of anti-aliased OS X fonts. Improvements in about:memory reports for tracking font memory usage. Improved performance on Windows systems without hardware acceleration. Fixed an issue that prevented users from updating Firefox for Mac unless they originally installed Firefox. Now, those users as well as any user with administrative credentials can update Firefox. Ended Firefox for Mac support for OS X 10.6, 10.7, and 10.8. Ended Firefox for Windows support for SSE processors. Removed Firefox Hello. Re-enabled the default for Graphite2 font shaping. Added a Cause column to the Network Monitor to show what caused each network request. Introduced web speech synthesis API.
49.0.1	September 23, 2016	Desktop Off-cycle stability update. Mitigated a startup crash issue caused by Websense (Windows only).
49.0.2	October 20, 2016	Off-cycle security and stability update. Asynchronous rendering of the Flash plugins for desktop is now enabled by default. This should improve performance and reduce crashes for sites that use the Flash plugin. Changed D3D9 default fallback preference to prevent graphical artifacts. Fixed a network issue that prevents some users from seeing the Firefox UI on startup. Fixed a web compatibility issue with Array.prototype.values Fixed a web compatibility issue with file uploads on Android. Diagnostic information on timing for tab switching. Fix for a Canvas filters graphics issue affecting HTML5 apps. End-of-life 49.0.x product line on November 15, 2016.
50.0	November 15, 2016	Official Firefox 50.0 release. Playback video on more sites without plugins with WebM EME Support for Widevine on Windows and Mac. Improved performance for SDK extensions or extensions using the SDK module loader. Added download protection for a large number of executable file types on Windows, Mac and Linux. Increased availability of WebGL to more than 98 percent of users on Windows 7 and newer. Added Guarani (gn) locale. Added option to Find in page that allows users to limit search to whole words only. Updates to keyboard shortcuts. Set for a preference to have Ctrl+Tab cycle through tabs in recently used order. View for a page in Reader Mode by using Ctrl+Alt+R (Command+Alt+R on Mac). Various security fixes. Blocked versions of libavcodec older than 54.35.1. Added a built-in Emoji set for operating systems without native Emoji fonts (Windows 8.0 and lower and Linux). Changes for web developers. Android Added support for HLS videos via player overlay. Simplified the user interface by combining the Recent Tabs and History panels.
50.0.1	November 28, 2016	Desktop Off-cycle security and stability update. Fixed an issue where Firefox crashes with 3rd party Chinese IME when using IME text.
50.0.2	November 30, 2016	Off-cycle security update. Fixed a zero-day exploit in the wild among other exploits.
50.1.0	December 13, 2016	Regular security update. End-of-life 50.x.x product line on January 24, 2017.
51.0	January 24, 2017	Official Firefox 51.0 release. Added support for FLAC (Free Lossless Audio Codec) playback. Improved reliability of browser data sync. An even faster E10s! Tab Switching is better! Added Georgian (ka) and Kabyle (kab) locales. A warning is displayed when a login page does not have a secure connection. Added support for WebGL 2, with advanced graphics rendering features like transform feedback, improved texturing capabilities, and a new sophisticated shading language. Firefox will save passwords even in forms that do not have “submit” events. Improved video performance for users without GPU acceleration for less CPU usage and a better full screen experience. Added a zoom button in the URL bar: Displays percent above or below 100 percent when a user has changed the page zoom setting from the default. Lets users return to the default setting by clicking on the button. Users can view passwords in the save password prompt before saving them. Removed Belarusian (be) locale. Various security fixes. Updated to NSS 3.28.1. Re-enabled E10s support for Russian (ru) locale. Use of 2D graphics library (Skia) for content rendering on Linux. Android Added Nepali (ne-NP), Bulgarian (bg) and Kabyle (kab) locales.
51.0.1	January 26, 2017	Desktop Off-cycle security and stability update. Fixed an issue in which multiprocess incompatibility did not correctly register with some add-ons. Fixed an issue in which geolocation was not working on Windows.
51.0.2	February 6, 2017	Android Off-cycle stability update. Fix for a crash caused by an Android library (Palette) on some x86 devices.
51.0.3	February 9, 2017	Android Off-cycle stability update. Fix for a build issue which was causing some crashes on some x86 architectures. End-of-life 51.0.x product line on March 7, 2017.

Firefox 52 through 59

Logo used from Firefox 57

Firefox 52 and Firefox 52 ESR were released on March 7, 2017 for desktop (both) and Android (no ESR). An important aspect of Firefox ESR 52.0 is that it is the first ESR version based on Firefox Electrolysis (Firefox 48) code base. Firefox 52 added support for WebAssembly (while disabled in Firefox ESR 52), an emerging standard that brings near-native performance to Web-based games, apps, and software libraries without the use of plugins; automatic captive portal detection, for easier access to Wi-Fi hotspots; user warnings for non-secure HTTP pages with logins (desktop); and display of media controls to pause or resume playback on the Android notification bar. Firefox 52 dropped support for NPAPI plugins like Microsoft Silverlight and Java with the exception of Adobe Flash Player (except the ESR version which still supports NPAPI).

Firefox 53 was released on April 19, 2017 for both desktop and Android. Starting with Firefox 53, Microsoft Windows support is exclusively for Windows 7 and above. Among the many additions are: improved graphics stability for Windows users with the addition of compositor process separation, light and dark "compact" themes available, based on the Firefox Developer Edition theme, removal of support for 32-bit macOS and Linux support for processors older than Pentium 4 and AMD Opteron; new visual design for audio and video controls, support for WebM video with alpha compositing, which allows playing videos with transparent backgrounds (desktop), Reader Mode displaying estimated reading time for the page (desktop and Android), and enabling two columns tabs setting in portrait mode (Android).

Firefox 54 was released on June 13, 2017 for both desktop and Android. Among the many additions are: simplifying the download button and download status panel, added support for multiple content processes, and the ability to create and save custom devices in Responsive web design mode (desktop), and improved audio and video playback in the browser, and improved bookmarks sync performance (Android).

Firefox 55 was released on August 8, 2017 for both desktop and Android. Among the many additions are: the launch of Windows support for WebVR, bringing immersive experiences to the web, options that let users optimize recent performance improvements, simplification of installation process with a streamlined Windows stub installer, improvement of address bar functionality, simplification of printing from Reader Mode (desktop), and the option to accessibility settings to respect the system's set font size when displaying web pages (Android). This is also the last version to support Android Ice Cream Sandwich.

Firefox 56 was released on September 28, 2017 for both desktop and Android. Among the many additions are: a new layout for the "Preferences" page, the launch of Firefox Screenshots, support for address form autofill, hardware acceleration for AES-GCM, update of the Safe Browsing protocol to version 4, and improved security or verifying update downloads (desktop), and improvement of support for WebExtensions, and the end of support for Adobe Flash (Android). Starting with this version, Android support is exclusively for Android Jelly Bean and above.

Firefox 57 was released on November 14, 2017 for desktop and Android with the name Firefox Quantum. ZDNet dubbed it a "comeback" following years of falling market share against Google Chrome. The release included a new interface design, codenamed "Photon", and a new rendering engine almost twice as fast as the previous one used. One of the largest visual changes in Photon was the removal of the search box from the address bar. Firefox 57 no longer supports legacy add-ons using XUL technologies. That same day, Mozilla announced that Google would be the default search engine in the USA and Canada, a departure from Yahoo, which had been the default search engine in the USA and Canada since 2014.

Firefox 58 was released on January 23, 2018 for desktop and Android. Among the additions were: support for credit card autofill, the drop of support for user profiles in previous versions of Firefox, a warning to alert users and site owners of planned security changes to sites affected by the gradual distrust plan for the Symantec certificate authority (desktop), full screen bookmark management with folder support, support for FLAC (Free Lossless Audio Codec) playback, ability to change the status bar color in themes, and removal of the Firefox Search widget from home screen (Android).

Firefox 59 was released on March 13, 2018 for desktop and Android. Among the additions were: faster load times and improved graphics, improved Real-Time Communications (RTC) capabilities, additional features for Firefox Screenshots, support for W3C specs for pointer events, and Private Browsing Mode's removal of path information from referrers to prevent cross-site tracking (desktop), and the addition of Firefox as an Assist app, support for HLS (HTTP Live Streaming) playback for improved compatibility with video sites, and removal of the "about:" page.

Release history of Firefox 52 – 59
Version	Release date	Release type and highlights
52.0	March 7, 2017	Official Firefox 52.0 release. First release to implement WebAssembly. Added support for WebAssembly, an emerging standard that brings near-native performance to Web-based games, apps, and software libraries without the use of plugins. Added automatic captive portal detection, for easier access to Wi-Fi hotspots. When accessing the Internet via a captive portal, Firefox will alert users and open the portal login page in a new tab. Enabled multi-process Firefox for Windows users with touch screens Added user warnings for non-secure HTTP pages with logins. Firefox now displays a “This connection is not secure” message when users click into the username and password fields on pages that don’t use HTTPS. Implemented the Strict Secure Cookies specification which forbids insecure HTTP sites from setting cookies with the "secure" attribute. In some cases, this will prevent an insecure site from setting a cookie with the same name as an existing "secure" cookie from the same base domain. Enhanced Sync to allow users to send and open tabs from one device to another. Improved text input for third-party keyboard layouts on Windows. This will address some keyboard layouts that: have chained dead keys. input two or more characters with a non-printable key or a dead key sequence. input a character even when a dead key sequence failed to compose a character. Removed support for Netscape Plugin API (NPAPI) plugins other than Flash. Silverlight, Java, Acrobat and the like are no longer supported. Removed Battery Status API to reduce fingerprinting of users by trackers. Improved experience for downloads: Notification in the toolbar when a download fails. Quick access to five most recent downloads rather than three. Larger buttons for canceling and restarting downloads. Displaying (but allowing users to override) an “Untrusted Connection” error when encountering SHA-1 certificates that chain up to a root certificate included in Mozilla’s CA Certificate Program. (Note: Firefox continues to permit SHA-1 certificates that chain to manually imported root certificates.) Migrated Firefox users on Windows XP and Windows Vista operating systems to the extended support release (ESR) version of Firefox. When not using Direct2D on Windows, Skia is used for content rendering. Enabled CSS Grid Layout, opening up a world of new possibilities for graphic design. Redesigned Responsive Design Mode to include device selection, network throttling, and more. Improved security for screen sharing, which now shows a preview and no longer requires a whitelisted domain. Android Reduced APK file size by more than 5 MB for faster download and installation. Display of media controls to pause or resume playback on the Android notification bar. This gives users easy access to controls and allows them to see when audio or video is playing (and consuming mobile data) on Firefox.
52.0.1	March 17, 2017	Off-cycle security update. Various security fixes.
52.0.2	March 28, 2017	Off-cycle stability update. Fixed use of Nirmala UI as fallback font for additional Indic languages. Fix for loading tab icons on session restore. Fix for a crash on startup on Linux. Fix for new installs erroneously not prompting to change the default browser setting. Android Disabled presentation API to avoid page loading delays. Display of end-of-life message on non-NEON devices. End-of-life 52.0.x product line on April 19, 2017.
52.0esr	March 7, 2017	Official Firefox 52.0 Extended Support Release (ESR).
52.0.1esr	March 17, 2017	Off-cycle security update. Same changelog of 52.0.1
52.0.2esr	March 28, 2017	Off-cycle stability update. Same changelog of 52.0.2
52.1.0esr	April 19, 2017	Regular security and stability update. Various security, stability, and regression fixes.
52.1.1esr	May 5, 2017	Off-cycle security update. Various security fixes.
52.1.2esr	May 19, 2017	Off-cycle stability update. Fixed hangs when using a proxy with NTLM authentication.
52.2.0esr	June 13, 2017	Regular security and stability update. Various security fixes Improved file type recognition on Windows
52.2.1esr	June 29, 2017	Off-cycle stability update. Fixed an issue in which printing text does not work on Windows when Direct2D is disabled
52.3.0esr	August 8, 2017	Regular security and stability update. Various security fixes Various stability and regression fixes
52.4.0esr	September 28, 2017	Regular security and stability update. Various security fixes Various stability and regression fixes
52.4.1esr	October 9, 2017	Off-cycle stability update. Fixed a crash when using the color picker on macOS 10.13 Fixed a crash when playing videos on macOS 10.13
52.5.0esr	November 14, 2017	Regular security and stability update. Various security fixes Various stability and regression fixes
52.5.2esr	December 7, 2017	Off-cycle security update. Various security fixes
52.5.3esr	December 28, 2017	Off-cycle stability update. Fix for a crash reporting issue that inadvertently sends background tab crash reports to Mozilla without user opt-in
52.6.0esr	January 23, 2018	Regular security and stability update. Various stability and regression fixes Various security fixes
52.7.0esr	March 13, 2018	Regular security and stability update. Various stability and regression fixes Various security fixes
52.7.1esr	March 14, 2018	Off-cycle stability update. Fixed an issue in which the search is broken for Italian "it" locale in Firefox ESR 52.7.0
52.7.2esr	March 16, 2018	Off-cycle security update. Various security fixes
52.7.3esr	March 26, 2018	Off-cycle security update. Various security fixes
52.7.4esr	April 30, 2018	Off-cycle stability update. Fix for compatibility with Windows 10 April 2018 update.
52.8.0esr	May 9, 2018	Regular security and stability update. Various stability and regression fixes Performance improvements to the Safe Browsing service to avoid slowdowns while updating site classification data
52.8.1esr	June 6, 2018	Off-cycle security update. Various security fixes
52.9.0esr	June 26, 2018	Regular security update. Various security fixes Last release for Windows XP and Windows Vista. Last release for 32-bit Mac OS X. End-of-life 52.x.x ESR product line on September 5, 2018.
53.0	April 19, 2017	Official Firefox 53.0 release. Improved graphics stability for Windows users with the addition of compositor process separation (Quantum Compositor). Two new 'compact' themes available in Firefox, dark and light, based on the Firefox Developer Edition theme. Lightweight themes are now applied in private browsing windows. Reader Mode now displays estimated reading time for the page. Windows 7+ users on 64-bit OS can select 32-bit or 64-bit versions in the stub installer. Various security fixes. Updated the design of site permission requests to make them harder to miss and easier to understand. Windows XP and Vista are no longer supported. XP and Vista users running Firefox 52 will continue to receive security updates on Firefox ESR 52. 32-bit Mac OS X is no longer supported. 32-bit Mac OS X users can switch to Firefox ESR 52 to continue receiving security updates.. Updates for Mac OS X are smaller in size compared to updates for Firefox 52. The last few characters of shortened tab titles fade out instead of being replaced by ellipses to keep more of the title visible. Ended Firefox Linux support for processors older than Pentium 4 and AMD Opteron New visual design for audio and video controls. Support for WebM video with alpha, which allows playing videos with transparent backgrounds. Changes for web developers. Android Right to Left Language Support – Arabic (ar), Urdu (ur), Hebrew (he) and Persian (fa) Users can enable two columns tabs setting in portrait mode. Long press on a search suggestion removes it from browser history.
53.0.1	April 27, 2017	Android Off-cycle stability update. Fixed a rare condition that could prevent opening restored tabs. Fix for accessibility issue with TalkBack. Fix for a crash with the Bluhell Firewall add-on.
53.0.2	May 5, 2017	Off-cycle security and stability update. Various security fixes. The non-standard showDialog argument to window.find is now ignored. Right-to-left locales will now display the search bar correctly. Prevented video corruption on affected devices. Desktop Made form validation errors and date picker panel visible to the user Android Fix for issues with Android integration.
53.0.3	May 19, 2017	Desktop Off-cycle stability update. Fixed hangs when using a proxy with NTLM authentication. Fixed excessive resource usage from the captive portal detection service. Bumped preloaded security information expiration times. End-of-life 53.0.x product line on June 13, 2017.
54.0	June 13, 2017	Official Firefox 54.0 release. Simplified the download button and download status panel. Added support for multiple content processes (e10s-multi). Added Burmese (my) locale. Moved the mobile bookmarks folder to the main bookmarks menu for easier access. Added ability to create and save custom devices in Responsive Design Mode. Additional changes for web developers. Android Added Bulgarian (bg) and Kabyle (kab) locales. Fixed formatting for right-to-left languages, including formatting of preference names in about:config. Improved audio and video playback in the browser. Improved bookmarks sync performance. Changes during Developer Edition releases Last Developer Edition build that is based on "Aurora" build. Firefox Developer Edition will be based on the "Beta" build afterwards.
54.0.1	June 29, 2017	Off-cycle stability update. Fix for a display issue of tab title. Fix for a display issue of opening new tab. Fix for a display issue when opening multiple tabs. Fix for a tab display issue when downloading files. Desktop Fix for a PDF printing issue. Fix for a Netflix issue on Linux. Android Fix for an inconsistent locale display issue Fix for a crash in tabs tray menu Fix for issues with navigation End-of-life 54.0.x product line on August 8, 2017.
55.0	August 8, 2017	Official Firefox 55.0 release. Launched Windows support for WebVR, bringing immersive experiences to the web. Added options that let users optimize recent performance improvements Setting to enable Hardware VP9 acceleration on Windows 10 Anniversary Update for better battery life and lower CPU usage while watching videos Setting to modify the number of concurrent content processes for faster page loading and more responsive tab switching Simplified installation process with a streamlined Windows stub installer Firefox for Windows 64-bit is now installed by default on 64-bit systems with at least 2GB of RAM Full installers with advanced installation options are still available Improved address bar functionality Search with any installed one-click search engine directly from the address bar Search suggestions appear by default When entering a hostname (like pinterest.com) in the URL bar, Firefox resolves to the secure version of the site (https://www.pinterest.com) instead of the insecure version (http://www.pinterest.com) when possible Updated Sidebar for bookmarks, history, and synced tabs so it can appear at the right edge of the window as well as the left Added support for stereo microphones with WebRTC Simplified printing from Reader Mode Updated Firefox for OS X and macOS to allow users to assign custom keyboard shortcuts to Firefox menu items via System Preferences Browsing sessions with a high number of tabs are now restored in an instant Make screenshots of webpages, and save them locally or upload them to the cloud. This feature will undergo A/B testing and will not be visible for some users. Added Belarusian (be) locale Various security fixes Modernized application update UI to be less intrusive and more aligned with the rest of the browser. Only users who have not restarted their browser 8 days after downloading an update or users who opted out of automatic updates will see this change. Made the Adobe Flash plugin click-to-activate by default and allowed only on http:// and https:// URL schemes. (This change will not be visible to all users immediately.) Firefox does not support downgrades, even though this may have worked in past versions. Users who install Firefox 55+ and later downgrade to an earlier version may experience issues with Firefox. Sites that don’t use SSL can no longer access Geolocation APIs to determine a user’s physical location Headless mode supported on linux Android Added actions to manage tabs. You can now reorder tabs by tapping and holding a tab in the tabs tray (or in the tab strip on tablets). Added Greek (el) and Lao (lo) locales Various security fixes Added option to accessibility settings to respect the system's set font size when displaying web pages Video that is not visible will stop rendering to conserve power (audio will still continue) Note: Firefox 55 is the last version that supports devices running Android 4.0
55.0.1	August 10, 2017	;Desktop Off-cycle stability update. Fix for a rendering issue with some PKCS#11 libraries. Fix for a problem causing What's new pages not to be displayed. Fix for a regression in the tab restoration process. Disabled the predictor prefetch.
55.0.2	August 16, 2017	Off-cycle stability update. Fix for a potential issue when the username had some specific characters in the path. Fix for an issue with new installation notification for sideload add-ons. Fix for performance regressions with WebExtension. Fix for a regression with the popup menu. Android Fix for an issue with tab restoration Fix for a crash with Telemetry Fixed: Blacklisting of Galaxy S4 SPH-L720 model for the adaptive playback feature Disabled the predictor prefetch Last release to support Android 4.0.x (Ice Cream Sandwich)
55.0.3	August 25, 2017	;Desktop Off-cycle stability update. Fixed file uploads to some websites, including YouTube. Fix for an issue with addons when using a path containing non-ASCII characters. End-of-life 55.0.x product line on September 28, 2017.
56.0	September 28, 2017	Official Firefox 56.0 release. Launched Firefox Screenshots, a feature that lets users take, save, and share screenshots without leaving the browser Added support for address form autofill (en-US only) Updated Preferences Added search tool so users can find a specific setting quickly Reorganized preferences so users can more easily scan settings Rewrote descriptions so users can better understand choices and how they affect browsing Revised data collection choices so they align with updated Privacy Notice and data collection strategy Media opened in a background tab will not play until the tab is selected Improved Send Tabs feature of Sync for iOS and Android, and Send Tabs can be discovered even by users without a Firefox Account Replaced character encoding converters with a new Encoding Standard-compliant implementation written in Rust Added hardware acceleration for AES-GCM Updated the Safe Browsing protocol to version 4 Reduced update download file size by approximately 20 percent Improved security for verifying update downloads Added Layout Panel to CSS Grid DevTools Android Improved support for WebExtensions on Android Improved power consumption and performance for WebRTC with the use of hardware encoders Added Zapoteco (zam) and Belarusian (be) locales Ended support for Flash Ended support for devices running Android 4.0
56.0.1	October 9, 2017	;Desktop Off-cycle stability update. Blocked D3D11 when using Intel drivers on Windows 7 systems with partial AVX support. Users of 32-bit Firefox on 64-bit Windows are migrated to 64-bit Firefox for increased stability and security.
56.0.2	October 26, 2017	;Desktop Off-cycle stability update. Disabled Form Autofill completely on user request. Fix for video-related crashes on Windows 7. Corrected detection for 64-bit GSSAPI authentication. Fix for shutdown crash. End-of-life 56.0.x product line on November 14, 2017.
57.0	November 14, 2017	Official Firefox 57.0 release. Firefox 57 ("Quantum") A completely new browsing engine, designed to take full advantage of the processing power in modern devices A redesigned interface with optimizations for touch screens A unified address and search bar. New installs will see this unified bar A revamped new tab page that includes top visited sites, recently visited pages, and recommendations from Pocket (in the US, Canada, and Germany) An updated product tour to orient new and returning Firefox users AMD VP9 hardware video decoder support for improved video playback with lower power consumption An expanded section in preferences to manage all website permissions Various security fixes Firefox now exclusively supports extensions built using the WebExtension API, and unsupported legacy extensions will no longer work The browser's autoscroll feature, as well as scrolling by keyboard input and touch-dragging of scrollbars, now use asynchronous scrolling. These scrolling methods are now similar to other input methods like mousewheel, and provide a smoother scrolling experience The content process now has a stricter security sandbox that blocks filesystem reading and writing on Linux, similar to the protections for Windows and macOS that shipped in Firefox 56 Middle mouse paste in the content area no longer navigates to URLs by default on Unix systems Removed the toolbar Share button Some older versions of the ATOK IME, including ATOK 2006, 2008, 2009 and 2010, can cause crashes and are therefore disabled on the Windows 64-bit version of Firefox Quantum The default font for Japanese text is now Meiryo A complete visual refresh of both the Light and Dark DevTools themes, matching the new visual style of Firefox Quantum The Inspector shows the values of CSS variables on hover Completely new and re-designed Console panel. Joining the Debugger and the Network Monitor, the Console has been rewritten using modern web technologies such as React and Redux. It now also allows to inspect objects in context. Android Performance improvements for faster page loading and stability Updated interface, including a revamped new tab page that includes top visited sites, recently visited pages, and recommendations from Pocket (in the US, Canada and Germany) Video decoding is shut down when the tab playing the media is sent to the background. Video resumes when the tab is brought to the foreground. Audio will not be affected Added an option to enable tracking protection outside of private browsing Automatically enabled private mode on compatible keyboards during private browsing Long URLs in the URL bar are now scrollable Added Wolof (wo) locale Firefox for Android now exclusively supports extensions built using the WebExtension API, and unsupported legacy extensions will no longer work Android Apps can now launch Firefox Custom Tabs
57.0.1	November 29, 2017	Off-cycle security and stability update. Fix for a video color distortion issue on YouTube and other video sites with some AMD devices. Fix for an issue with prefs.js when the profile path has non-ASCII characters. Various security fixes. Fixed an issue in which Google map crashes on macOS with Intel HD Graphics 3000. Blocked injection of a client library associated with the RealPlayer Free player which is known to cause performance problems in Firefox. Android Fixed an issue in which Stop button no longer appears immediately after starting a navigation. Various security fixes.
57.0.2	December 7, 2017	;Desktop Off-cycle stability update. Blocked old versions of G Data Endpoint Security for crashing Firefox on start up - Windows only Fix for a regression with WebGL and D3D9 - Windows only
57.0.3	December 28, 2017	;Desktop Off-cycle stability update. Fix for crash reporting issue that inadvertently sends background tab crash reports to Mozilla without a user opt-in.
57.0.4	January 4, 2018	Off-cycle security update. Security fixes to address the Meltdown and Spectre timing attacks. End-of-life 57.0.x product line on January 23, 2018.
58.0	January 23, 2018	Official Firefox 58.0 release. Performance improvements, including: Rendering graphics for Windows users by using Off-Main-Thread Painting (OMTP) Loading pages faster by changing how Firefox caches and retrieves JavaScript Improvements to Firefox Screenshots: Copy and paste screenshots directly to your clipboard Firefox Screenshots now works in Private Browsing mode Added support for credit card autofill Added Nepali (ne-NP) locale Users can enable Tracking Protection at all times. Fonts installed in non-standard directories will no longer appear blank for Linux users Various security fixes User profiles created in Firefox 58 (and in future releases) are not supported in previous versions of Firefox. Users who downgrade to a previous version should create a new profile for that version. Added a warning to alert users and site owners of planned security changes to sites affected by the gradual distrust plan for the Symantec certificate authority Implemented the PerformanceNavigationTiming API Added PerformanceResourceTiming.workerStart so sites can measure service worker startup time Android Performance improvements, including: Support for Progressive Web Apps Loading pages faster by changing how Firefox caches and retrieves JavaScript Added ability to Sync only over non-metered connections (e.g., WiFi). Setting available via Sync Preferences. Added full screen bookmark management with folder support Added support for FLAC (Free Lossless Audio Codec) playback Added ability to change the status bar color in themes Added Bengali from Bangladesh (bn-BD) and Nepali (ne-NP) locales Removed the Firefox Search widget from home screen Updated the Safe Browsing protocol to version 4
58.0.1	January 29, 2018	Off-cycle security and stability update. Security fix. Fixed an issue in which, when using certain non-default security policies on Windows (for example with Windows Defender Exploit Protection or Webroot security products), Firefox 58.0 would fail to load pages. Android Fixed performance issue whereby some installations were initially slow to load pages.
58.0.2	February 7, 2018	Off-cycle stability update. Avoided a signature validation issue during update on macOS Blocklisted graphics drivers related to off main thread painting crashes. Fixed tab crash during printing. Fix for clicking links and scrolling emails on Microsoft Hotmail and Outlook (OWA) webmail. Android Fixed an issue in which, if the user cancels a download by exiting our app chooser dialogue without choosing anything, the download continues invisibly in background. End-of-life 58.0.x product line on March 13, 2018.
59.0	March 13, 2018	Official Firefox 59.0 release. Performance enhancements: Faster load times for content on the Firefox Home page Faster page load times by loading either from the networked cache or the cache on the user’s hard drive (Race Cache With Network) Improved graphics rendering using Off-Main-Thread Painting (OMTP) for Mac users Drag-and-drop to rearrange Top Sites on the Firefox Home page, and customize new windows and tabs in other ways Added features for Firefox Screenshots: Basic annotation lets the user draw on and highlight saved screenshots Recropping to change the viewable area of saved screenshots Enhanced WebExtensions API including better support for decentralized protocols and the ability to dynamically register content scripts Improved Real-Time Communications (RTC) capabilities. Implemented RTP Transceiver to give pages more fine grained control over calls Implemented features to support large scale conferences Added support for W3C specs for pointer events and improved platform integration with added device support for mouse, pen, and touch screen pointer input Added the Ecosia search engine as an option for German Firefox Added the Qwant search engine as an option for French Firefox Added settings in about:preferences to stop websites from asking to send notifications or access your device’s camera, microphone, and location, while still allowing trusted websites to use these features Various security fixes Firefox Private Browsing Mode will remove path information from referrers to prevent cross-site tracking Android Added Firefox as an Assist App so users can start a search by long-pressing the home button Added support for HLS (HTTP Live Streaming) playback for improved compatibility with video sites Firefox Private Browsing Mode will remove path information from referrers sent to third parties to help prevent third-party data leakage The "about:" page was removed Locked video full screen in landscape mode
59.0.1	March 16, 2018	Off-cycle security update. Various security fixes.
59.0.2	March 26, 2018	Off-cycle security and stability update. Fixed invalid page rendering with hardware acceleration enabled Fixed an issue in which Windows 7 users with touch screens or certain 3rd party desktop applications which interact with Firefox through accessibility services may experience random browser crashes Fixed an issue in which browser keyboard shortcuts (eg copy Ctrl+C) don't work on sites that use those keys with resistFingerprinting enabled Fixed high CPU / memory churn caused by third-party software on some computers. Fixed an issue in which users who have configured an "automatic proxy configuration URL" and want to reload their proxy settings from the URL will find the Reload button disabled in the Connection Settings dialog when they select Preferences/Options > Network Proxy > Settings Fixed an issue in which URL fragment identifiers break Service Worker responses. Fixed an issue in which users trying to cancel a print around the time it completed would continue to get intermittent crashes Fixed broken getUserMedia (audio) on DragonFly, FreeBSD, NetBSD, OpenBSD. Video chat apps either wouldn't work or be always muted Various security fixes Android Fixed top crasher on Firefox for Android Fixed an issue in which URL fragment identifiers break Service Worker responses
59.0.3	April 30, 2018	;Desktop Off-cycle stability update. Fix for compatibility with Windows 10 April 2018 update. End-of-life 59.0.x product line on May 9, 2018.

Firefox 60 through 67

Firefox 60 and Firefox 60 ESR were released on May 9, 2018 for desktop (both) and Android (no ESR). A policy engine that allows customized Firefox deployments in enterprise environments, using Windows Group Policy or a cross-platform JSON file, enhancements to New Tab / Firefox Home, redesigned Cookies and Site Storage section in Preferences for greater clarity and control of first- and third-party cookies, the application of Quantum CSS to render browser UI, support for Web Authentication API, which allows USB tokens for website authentication, an option for Linux users to show or hide page titles in a bar at the top of the browser, improved WebRTC audio performance and playback for Linux users (desktop), exclusive support for extensions built using the WebExtension API (ESR), the implementation of Quantum CSS (also known as Stylo) in Android for faster page rendering; and the addition of View Page Source option to the Page Action menu (Android).

Firefox 61 was released on June 26, 2018 for both desktop and Android. Among the many additions were: Improvements for dark theme support across the entire Firefox user interface, added support to allow WebExtensions to hide tabs, improved bookmark syncing, convenient access to more search engines (desktop), improved security and enhanced performances (both), and the fix for a recurring crash on Samsung Galaxy S8 devices running Android Oreo (Android).

Firefox 62 was released on September 5, 2018 for both desktop and Android. Among the many additions were: FreeBSD support for WebAuthn, a preference that allows users to distrust certificates issued by Symantec in advance of removing all trust for Symantec-issued certificates in Firefox 63, improved graphics rendering for Windows users without accelerated hardware using Parallel-Off-Main-Thread Painting, CSS Variable Fonts (OpenType Font Variations) support, and support for CSS Shapes, allowing for richer web page layouts (desktop), and improved scrolling performance, faster page load times over WiFi connections by loading from the network cache if disk cache is slow, and “Product and feature tips” toggle in Notifications settings (Android).

Firefox 63 was released on October 23, 2018 for both desktop and Android. Among the many additions and changes were: Performance and visual improvements for Windows and macOS users, content blocking, WebExtensions running in their own process in Linux, recognition of the operating system accessibility setting for reducing animation, the addition of Amazon and Google as Top Sites tiles on the Firefox Home (New Tab) page, the removal of the "Never Check for Updates" option from "about:preferences" and "Open in Sidebars" feature from the Library (desktop), support for Picture-In-Picture video, and use of notification channels (Android).

Firefox 64 was released on December 11, 2018 for desktop only. Among the many additions and changes were: better recommendations, enhanced tab management, easier performance management, improved performance for Mac and Linux users, by enabling link time optimization (Clang LTO), more seamless sharing on Windows, the option to remove add-ons using the context menu on their toolbar buttons, TLS certificates issued by Symantec that are no longer trusted by Firefox, and the availability of WebVR on macOS. Three days later, Firefox 64.0.1 was released for Android only. Among the many additions and changes were: faster and more responsive scrolling and fixes for performance lags for users with installed password manager apps and an issue that resulted in the loading indicator using too much CPU and power.

Firefox 65 was released on January 29, 2019, for both desktop and Android. Among the many additions and changes were: improved performance and web compatibility, with support for the WebP image format; enhanced security for macOS, Linux, and Android users via stronger stack smashing protection which is now enabled by default for all platforms (both desktop and Android); enhanced tracking protection; updated language settings in Preferences; support for Handoff on macOS; better video streaming experience for Windows users; easier performance management; improved pop-up blocker; the availability of Firefox for Windows with 32- and 64-bit MSI installers for easier enterprise deployments; additional support for Flexbox (desktop); and the restoration of Chromecast controls to the location bar (Android).

Firefox 66 was released on March 19, 2019, for both desktop and Android. Among the many additions and changes were: Prevention of websites from automatically playing sound, smoother scrolling (both), improved search experience and performance and better user experience for extensions, the addition of basic support for macOS Touch Bar and of support for Windows Hello on Windows 10, the enabling of AV1 support on 32-bit Windows and MacOS (desktop), and the addition of support to open files from external storage, such as an SD card (Android).

Legend:	Former release	Extended Support Release (ESR)	Current	Beta	Future official release	Future test release	Top

Release history of Firefox 60 – 67
Note: Dates in the future indicate a scheduled release date; they are subject to change in the event of unanticipated complications.
Version	Release date	Release type and highlights
60.0	May 9, 2018	Official Firefox 60.0 release. Added a policy engine that allows customized Firefox deployments in enterprise environments, using Windows Group Policy or a cross-platform JSON file. DNS over HTTPS (DOH) functionality available. Enhancements to New Tab / Firefox Home. Responsive layout that shows more content for users with wide-screen displays. Highlights section includes web sites saved to Pocket. More options to reorder sections and content on the page. Pocket Sponsored Stories will appear for a percentage of users in the US. Redesigned Cookies and Site Storage section in Preferences for greater clarity and control of first- and third-party cookies. Applied Quantum CSS to render browser UI. Added support for Web Authentication API, which allows USB tokens for website authentication. Enhanced camera privacy indicators: Firefox now turns off your camera and the camera's light when you disable video recording, and turns the camera and light on when you resume recording. Added an option for Linux users to show or hide page titles in a bar at the top of the browser. Improved WebRTC audio performance and playback for Linux users. Locale added: Occitan (oc). Various security fixes. Changed the Windows shortcut for entering Reader View to F9, for better compatibility with keyboard layouts that use AltGr. Bookmarks no longer support multiple keywords for the same URL unless the request has different POST data. TLS certificates issued by Symantec before June 1st, 2016 are no longer trusted by Firefox. Updated the Skia graphics library to milestone 66. Changes affecting developers. Android Implemented Quantum CSS (also known as Stylo) in Android for faster page rendering. Added View Page Source option to the Page Action menu. Various security fixes. Changes affecting developers.
60.0.1	May 16, 2018	Off-cycle stability update. Avoided overly long cycle collector pauses with some add-ons installed. Fixed an issue in which, after unchecking the "Sponsored Stories" option, the New Tab page now immediately stops displaying "Sponsored content" cards. On touchscreen devices, fixed momentum scrolling on non-zoomable pages. Fixed black map on Google Maps with updated Nvidia Web Drivers on macOS. Corrected use of the right default background when opening tabs or windows in high contrast mode. The Firefox uninstaller on Windows is now translated again. Restored translations of the Preferences panels when using a language pack. WebVR has been disabled by default on macOS. Android On touchscreen devices, fixed momentum scrolling on non-zoomable pages.
60.0.2	June 6, 2018	Off-cycle security and stability update. Updated to NSS 3.36.4 from 3.36.1: Fixed an issue in which connecting to a server that was recently upgraded to TLS 1.3 would result in a SSL_RX_MALFORMED_SERVER_HELLO error. Fix for a crash on macOS related to authentication tokens, e.g. PK11 or WebAuthn. Desktop Fix for missing nodes in the developer tools Inspector panel. Fix for font rendering when using third-party font managers on OS X 10.11 and earlier. Various security fixes. End-of-life 60.0.x product line on June 26, 2018.
60.0esr	May 9, 2018	Official Firefox 60.0 Extended Support Release (ESR). Firefox Quantum arrives in the ESR channel. Key features include: A completely new browser engine, designed to take full advantage of the processing power in modern devices A redesigned interface with a clean, modern appearance, consistent visual elements, and optimizations for touch screens A unified address and search bar. New installs will see this unified bar. A revamped new tab page that includes top visited sites, recently visited pages, and recommendations from Pocket (in the US, Canada, and Germany) An updated product tour to orient new and returning Firefox users Support for enterprise environments, with a policy engine that allows customized Firefox deployments using Windows Group Policy or a cross-platform JSON file Firefox now exclusively supports extensions built using the WebExtension API. Unsupported legacy extensions will no longer work in Firefox 60 ESR, but they will continue to work in Firefox 52 ESR, which will be supported until September 2018. DNS over HTTPS (DOH) functionality available. TLS certificates issued by Symantec before June 1st, 2016 are no longer trusted by Firefox. The "security.pki.distrust_ca_policy" preference can be set to 0 to reinstate trust in those certificates
60.0.1esr	May 16, 2018	Off-cycle stability update Same changelog of 60.0.1
60.0.2esr	June 6, 2018	Off-cycle security and stability update. Same changelog of 60.0.2
60.1.0esr	June 26, 2018	Regular security and stability update. Various security fixes Various stability and regression fixes
60.2.0esr	September 5, 2018	Regular security and stability update. Various security fixes Various stability and regression fixes
60.2.1esr	September 21, 2018	Off-cycle security and stability update. Disabled multiprocess support for users running old versions of the JAWS screen reader software Fixed a startup crash affecting users migrating from older ESR releases Cleaned up old NSS DB files after upgrading Various security fixes
60.2.2esr	October 2, 2018	Off-cycle security and stability update. Fixed hangs on macOS Mojave (10.14) when various dialog windows (upload, download, print, etc) are activated Various security fixes
60.3esr	October 23, 2018	Regular security and stability update. Various stability and regression fixes Various security fixes
60.4esr	December 11, 2018	Regular security and stability update. Updated list of currency codes to include Unidad Previsional (UYW) Various security fixes
60.5esr	January 28, 2019	Regular security update. Various security fixes
60.5.1esr	February 12, 2019	Off-cycle security update. Various security fixes
60.5.2esr	February 22, 2019	Off-cycle stability update. Fixed a frequent crash when reading various Reuters news articles
60.6esr	March 19, 2019	Regular security update. Various security fixes In the network connections settings, sites added to the "No proxy for" list will now honor that setting regardless of any other specified proxy settings
60.6.1esr	March 22, 2019	Off-cycle security update. Various security fixes End-of-life 60.x.x product line on October 22, 2019.
60.7esr	May 14, 2019
60.8esr	July 9, 2019
60.9esr	September 3, 2019
61.0	June 25, 2018	Official Firefox 61.0 release. Enhanced performance: Faster page rendering with Quantum CSS improvements and the new retained display list feature Faster switching between tabs on Windows and Linux WebExtensions now run in their own process on MacOS Convenient access to more search engines: You can now add search engines to the address bar “Search with” tool from the page action menu when on a webpage that provides an OpenSearch plugin Share links from Firefox for MacOS more easily: You can now share the URL of an active tab from the page actions menu in the address bar Improved security: On-by-default support for the latest draft of the TLS 1.3 specification Access to FTP subresources inside http(s) pages has been blocked A more consistent user experience: Improvements for dark theme support across the entire Firefox user interface More customization for tab management: added support to allow WebExtensions to hide tabs Improved bookmark syncing The settings for customizing your homepage and new tab page in Firefox have been added to a new Preferences section that can be accessed from Firefox at about:preferences#home. The settings can also be accessed via the gear icon on the New Tab page. Android Performance enhancements: Quantum CSS improvements which improve page rendering times Faster scrolling due to treating touch event listeners as passive by default Improved security: On-by-default support for the latest draft of the TLS 1.3 specification Fixed a recurring crash on Samsung Galaxy S8 devices running Android Oreo (8.0)
61.0.1	July 5, 2018	;Desktop Off-cycle stability update. Fixed broken website loading for Chinese users with accessibility enabled. Fixed missing content on the New Tab Page and the Home section of the Preferences page. Fixed loss of bookmarks under rare circumstances when upgrading from Firefox 60. Improved playback of Twitch 1080p video streams. Web pages no longer lose focus when a browser popup window is opened. Fixed launching of downloads without a file extension on Windows. Re-allowed downloading files from FTP sites via the "Save Link As" option when linked from HTTP pages. Fixed extensions being unable to override the default homepage in certain situations.
61.0.2	August 8, 2018	Off-cycle stability update. Adds support for automatically restoring your Firefox session after Windows restarts. Improved website rendering with the Retained Display List feature enabled. Fixed broken DevTools panels with certain extensions installed. Desktop Fixed a crash for users with some accessibility tools enabled. Android Fixed a crash on devices running Android KitKat 4.4 or earlier. End-of-life 61.0.x product line on September 5, 2018.
62.0	September 5, 2018	Official Firefox 62.0 release. Firefox Home (the default New Tab) now allows users to display up to 4 rows of top sites, Pocket stories, and highlights “Reopen in Container” tab menu option appears for users with Containers that lets them choose to reopen a tab in a different container In advance of removing all trust for Symantec-issued certificates in Firefox 63, a preference was added that allows users to distrust certificates issued by Symantec Added FreeBSD support for WebAuthn Improved graphics rendering for Windows users without accelerated hardware using Parallel-Off-Main-Thread Painting Support for CSS Shapes, allowing for richer web page layouts. This goes hand in hand with a brand new Shape Path Editor in the CSS inspector CSS Variable Fonts (OpenType Font Variations) support, which makes it possible to create beautiful typography with a single font file Updates for enterprise environments: AutoConfig is sandboxed to the documented API by default Added Canadian English (en-CA) locale Removed the description field for bookmarks Dark theme is automatically enabled in macOS 10.14 dark mode Changed the default setting to Enforce (3) for the security.pki.name_matching_mode preference Adobe Flash applets now run in a more secure mode using process sandboxing on macOS Users disconnecting from Sync are now offered the option to wipe their Firefox profile data (including bookmarks, passwords, history, cookies, and site data) from their desktop computer Changed how WebRTC handles screen sharing: When screen-sharing a window, the window will be brought to front Three-pane Inspector in Developer Tools separates the rules into its own panel Changes affecting developers Android Improved scrolling performance Faster page load times over WiFi connections by loading from the network cache if disk cache is slow “Product and feature tips” toggle in Notifications settings, allowing for more control over which notifications are shown WebRTC video sessions between Firefox for Android and Safari browsers works again
62.0.1	September 7, 2018	;Android Off-cycle stability update. Fixed a crash when navigating sites with WebGL content.
62.0.2	September 21, 2018	Off-cycle security and stability update. Unvisited bookmarks can once again be autofilled in the address bar. Fixed WebGL rendering issues. Updates from unpacked language packs no longer break the browser. Fixed fallback on startup when a language pack is missing. Fixed an issue in which profile refresh from the Windows stub installer restarts the browser. Properly restored window size and position when restarting on Windows. Avoided crash when sharing a profile with newer (as yet unreleased) versions of Firefox. Fixed an issue in which you do not undo removal of search engines when using a language pack. Fixed rendering of some web sites. Restored compatibility with some sites using deprecated TLS settings. Fix for screen share on macOS when using multiple monitors. Various security fixes. Android Fixed rendering of some web sites. Restored compatibility with some sites using deprecated TLS settings. Oversized quick share icons on Android 6.0 and newer. Various security fixes.
62.0.3	October 2, 2018	Off-cycle security and stability update. Various security fixes. Desktop Fixed hangs on macOS Mojave (10.14) when various dialog windows (upload, download, print, etc) are activated. Fixed playback of some encrypted video streams on macOS. End-of-life 62.0.x product line on October 23, 2018.
63.0	October 23, 2018	Official Firefox 63.0 release. Performance and visual improvements for Windows users Moved the build infrastructure of Firefox on Windows to the Clang toolchain, bringing important performance gains Firefox theme now matches the Windows 10 OS Dark and Light modes Performance improvements for macOS users Improved reactivity Faster tab switching WebGL power preferences allow non-performance-critical applications and applets to request the low-power GPU instead of the high-power GPU in multi-GPU systems Added content blocking, a collection of Firefox settings that offer users greater control over technology that can track them around the web. WebExtensions now run in their own process on Linux Firefox now warns about having multiple windows and tabs open when quitting from the main menu Firefox now recognizes the operating system accessibility setting for reducing animation Added search shortcuts for Top Sites: Amazon and Google appear as Top Sites tiles on the Firefox Home (New Tab) page (U.S. only) Resolved an issue that prevented the address bar from autofilling bookmarked URLs in certain cases In the Library, the Open in Sidebar feature for individual bookmarks was removed The option to Never check for updates was removed from about:preferences The Ctrl+Tab shortcut now displays thumbnail previews of your tabs and cycles through tabs in recently used order Refreshed visual style of Developer Tools menus to improve navigation and consistency The Dev Tools accessibility inspector is now enabled by default Added support for Web Components custom elements and shadow DOM The inspector now ships with a Font Editor that allows you to control non-variable as well as variable fonts Android Added support for Picture-In-Picture video Started using notification channels Locales added: English from Canada (en-CA), and Ligurian (lij) App now targets Oreo with security and performance improvements and support for new features
63.0.1	October 31, 2018	;Desktop Off-cycle stability update. Fixed an issue in which snippets are not loaded due to a missing element. Fixed an issue in which print preview always shows 30% scale when it is actually Shrink To Fit. Fixed an issue in which dialog displayed when closing multiple windows shows unreplaced %1$S placeholder in Japanese and potentially other locales.
63.0.2	November 7, 2018	;Android Off-cycle stability update. Fixed an issue in which session history popup breaks after one usage. Fixed flickering of (some) sticky elements on Twitter and other websites. Fixed a hang in Samsung Galaxy devices. Crash fixes.
63.0.3	November 15, 2018	;Desktop Off-cycle stability update. Fixed an issue in which games using WebGL (created in Unity) get stuck after very short time of gameplay. Fixed slow page loading for some users with specific proxy configurations. Disabled HTTP response throttling by default for causing bugs with videos in background tabs. Fixed an issue in which opening magnet links no longer works. Crash fixes. End-of-life 63.0.x product line on December 11, 2018.
64.0	December 11, 2018	;Desktop Official Firefox 64.0 release for desktop. Better recommendations: You may see suggestions in regular browsing mode for new and relevant Firefox features, services, and extensions based on how you use the web (for US users only). Enhanced tab management: You can now select multiple tabs from the tab bar and close, move, bookmark, or pin them quickly and easily. Easier performance management: The new Task Manager page found at about:performance lets you see how much energy each open tab consumes and provides access to close tabs to conserve power. Improved performance for Mac and Linux users, by enabling link time optimization (Clang LTO). More seamless sharing on Windows: Windows users can now share web pages using the native sharing experience. Added option to remove add-ons using the context menu on their toolbar buttons. Updated the policy engine on macOS to allow using configuration profiles to customize Firefox for enterprise deployments. Various security fixes. RSS feed preview and live bookmarks are available only via add-ons. TLS certificates issued by Symantec are no longer trusted by Firefox. about:crashes has been redesigned to make it clear when a crash is being submitted to Mozilla, as well as being clear that removing crashes locally does not remove them from crash-stats.mozilla.com. The macOS keyboard shortcut to add "www" and ".com" to a URL is now ctrl-enter instead of [apple]-enter. You may now overlay multiple CSS grids at the same time (up to 3) in the CSS Grid Inspector. The Web Console's command line now highlights JavaScript syntax. When hovering over elements in the Accessibility panel, the contrast ratio of text against background is now indicated. Added support for the new CSS scrollbar specification. WebVR is now available on macOS.
64.0.1	December 14, 2018	;Android Official Firefox 64.0 release for Android. Scrolling is faster and more responsive. Files downloaded after this update are no longer deleted when uninstalling Firefox. Fixed performance lags for users with installed password manager apps. Fixed an issue that resulted in the loading indicator using too much CPU and power. Various security fixes. TLS certificates issued by Symantec are no longer trusted by Firefox.
64.0.2	January 9, 2019	Off-cycle stability update. Fixed video stuttering on Youtube. Properly restored column sizes in developer tools inspector. Fix for updates for some lightweight themes. Desktop Fixed a browser crash on macOS. Updated the Japanese translation for missing strings. Android Fixed a crash when Firefox for Android is put in background. Fixed a crash when using Web Speech. End-of-life 64.0.x product line on January 29, 2019.
65.0	January 28, 2019	Official Firefox 65.0 release. Enhanced tracking protection: Simplified content blocking settings give users standard, strict, and custom options to control online trackers. Updated Language section in Preferences Support for Handoff on macOS A better video streaming experience for Windows users: Firefox now supports the next-generation, royalty-free video compression technology called AV1. Improved performance and web compatibility, with support for the WebP image format Various security fixes. Enhanced security for macOS, Linux, and Android users via stronger stack smashing protection which is now enabled by default for all platforms. Firefox will now warn you when closing a window (regardless of whether you have automatic session restore enabled for restart). Revamped Task Manager page found at about:performance Improved the pop-up blocker to prevent multiple pop-up windows from being opened by websites at the same time. Firefox for Windows is now available with 32- and 64-bit MSI installers for easier enterprise deployments. Launched a new Flexbox inspector tool that details Flexbox containers and helps debug Flex item sizes All CSS changes made in the Rules panel are now tracked in the new Changes tab. Added support for the Storage Access API on desktop platforms. Android Improved performance: Scrolling is faster and more responsive Improved performance and web compatibility, with support for the WebP image format Restored Chromecast controls to the location bar.
65.0.1	February 12, 2019	Off-cycle security and stability update. Fixed accidental requests to addons.mozilla.org when an addon recommendation doorhanger is shown. Improved playback of interactive Netflix videos. Fixed color management not working on macOS. Fixed incorrect sizing of the "Clear Recent History" window in some situations. Fixed looping CONNECT requests when using WebSockets over HTTP/2 from behind a proxy server. Fixed the "Enter" key not working on password entry fields for certain Linux distributions. Various stability and security fixes. Made support for <meta> viewport tags in Responsive Design Mode, initially enabled in Firefox 64, pref-controlled and off by default. Fixed looping CONNECT requests when using WebSockets over HTTP/2 from behind a proxy server. Desktop Fixed audio & video delays while making WebRTC calls. Fixed video sizing problems during some WebRTC calls. Android Various stability and security fixes.
65.0.2	February 28, 2019	;Desktop Off-cycle stability update. Fixed an issue with geolocation services affecting Windows users End-of-life 65.0.x product line on March 19, 2019.
66.0	March 19, 2019	Official Firefox 66.0 release. Firefox now prevents websites from automatically playing sound Improved search experience: Find a specific webpage faster when you have a lot of tabs open Easier search via a redesigned new tab in Private Windows Smoother scrolling: Scroll anchoring keeps content from jumping as images and ads load at the top of the page Improved performance and better user experience for extensions: Extensions now store their settings in a Firefox database, rather than individual JSON files, making every site you visit faster A redesigned keyboard shortcuts section in about:addons makes it easier to view and adjust default shortcuts Redesigned certificate error pages help you better understand and resolve issues, including identification of certificate issuers for anti-virus software Added basic support for macOS Touch Bar Experimenting with an improved Pocket experience in New Tab with different layouts and more topical content Improved performance and reduced crash rates by doubling web content loading processes from 4 to 8 Easier, passwordless security: Added support for Windows Hello on Windows 10 Enabled AV1 support on 32-bit Windows and MacOS The Dark and Light Firefox themes now override the system setting for title bar accent color on Windows 10 Linux users: Resolved an issue that caused Firefox to freeze when downloading files Various security fixes System title bar is hidden by default to match Gnome guideline for Linux users DevTools Inspector is now fully usable when the Debugger is paused Lowered priority of setTimeout and setInterval during page load to improve overall page load performance Fixed: <button> element is no longer special cased in event dispatch, per latest specifications Android Added support to open files from external storage, such as an SD card
66.0.1	March 22, 2019	Off-cycle security update. Various security fixes.
66.0.2	March 27, 2019	Off-cycle stability update. Desktop Fixed Web compatibility issues with Office 365, iCloud and IBM WebMail caused by recent changes to the handling of keyboard events. Crash fixes. Android Fixed frequent crashes on sites using the OpenH264 video codec for WebRTC.
66.0.3	April 10, 2019	;Desktop Off-cycle stability update. Address bar on tablets running Windows 10 now behaves correctly. Fixed performance issues with some HTML5 games. Fixed a bug with keypress events in IBM cloud applications. Fix for keypress events in some Microsoft cloud applications. Updated Baidu search plugin. End-of-life 66.0.x product line on May 14, 2019.
67.0b1	March 18, 2019	First Firefox 67.0 Developer Edition build.
67.0b1	March 18, 2019	First Firefox 67.0 Beta release.
67.0	May 14, 2019	Official Firefox 67.0 release. End-of-life 67.0.x product line on July 9, 2019.

Firefox 68 through 73

Release history of Firefox 68 – 73
Note: Dates in the future indicate a scheduled release date; they are subject to change in the event of unanticipated complications.
Version	Release date	Release type and highlights
68.0a1	March 18, 2019	First Firefox 68.0 Nightly build.
68.0b1	May 13, 2019	First Firefox 68.0 Developer Edition build.
68.0b1	May 13, 2019	First Firefox 68.0 Beta release.
68.0	July 9, 2019	Official Firefox 68.0 release. End-of-life 68.0.x product line on September 3, 2019.
68.0esr	July 9, 2019	Official Firefox 68.0 Extended Support Release (ESR).
68.1esr	September 3, 2019
68.2esr	October 22, 2019
68.3esr	December 10, 2019
69.0a1	May 13, 2019	First Firefox 69.0 Nightly build.
69.0b1	July 8, 2019	First Firefox 69.0 Developer Edition build.
69.0b1	July 8, 2019	First Firefox 69.0 Beta release.
69.0	September 3, 2019	Official Firefox 69.0 release. End-of-life 69.0.x product line on October 22, 2019.
70.0a1	July 8, 2019	First Firefox 70.0 Nightly build.
70.0b1	September 2, 2019	First Firefox 70.0 Developer Edition build.
70.0b1	September 2, 2019	First Firefox 70.0 Beta release.
70.0	October 22, 2019	Official Firefox 70.0 release. End-of-life 70.0.x product line on December 10, 2019.
71.0a1	September 2, 2019	First Firefox 71.0 Nightly build.
71.0b1	October 21, 2019	First Firefox 71.0 Developer Edition build.
71.0b1	October 21, 2019	First Firefox 71.0 Beta release.
71.0	December 10, 2019	Official Firefox 71.0 release.
72.0a1	October 21, 2019	First Firefox 72.0 Nightly build.
72.0b1	December 9, 2019	First Firefox 72.0 Developer Edition build.
72.0b1	December 9, 2019	First Firefox 72.0 Beta release.
73.0a1	December 9, 2019	First Firefox 73.0 Nightly build.

CPU architectures

x86 family

Native 64-bit builds are officially supported on Linux, macOS, and Windows (since version 42).

Mozilla made Firefox for 64-bit Linux a priority with the release of Firefox 4, labeling it as tier 1 priority. Since being labeled tier 1, Mozilla has been providing official 64-bit releases for its browser for Linux. Vendor-backed 64-bit support has existed for Linux distributions such as Novell/SUSE Linux, Red Hat Enterprise Linux, and Ubuntu prior to Mozilla's 64-bit support, even though vendors were faced with the challenge of having to turn off the 64-bit JIT compiler due to its instability prior to Firefox 4.

The official releases of Firefox for macOS are universal builds that include both 32-bit and 64-bit versions of the browser in one package, and have been this way since Firefox 4. A typical browsing session uses a combination of the 64-bit browser process and a 32-bit plugin process, because some popular plugins still are 32-bit. As of April 19, 2017, Firefox 53 has dropped support for 32-bit macOS.

The 32-bit and 64-bit versions of Windows can be used to run 32-bit Firefox. In late 2012, Mozilla announced 64-bit Windows builds would be stopped but later reversed the decision. As of April 2015, 64-bit Windows builds are available as 38.0 Beta and newer. 64-bit builds for Windows are officially supported as of November 2015 with the release of Firefox 42. All NPAPI plugins except Adobe Flash Player are blacklisted and unsupported on both 32-bit and 64-bit versions.

Other CPU architectures

Besides x86, Firefox also supported other CPU architectures including ARMv7, SPARC, PowerPC, and 68k on different tiers. Mozilla terminated support for PowerPC-based Macintosh computers with Firefox 3.6, but a third-party project known as TenFourFox ported several newer versions of Firefox, the latest being based on Firefox 45 ESR.

Mozilla Firefox timeline

Release compatibility

Operating system		Latest stable version	Support status
Windows	10 v1709 and later	Current stable version: 133.0 (ARM64)	2019–
		Old version, yet still maintained: 128.5.0esr (ARM64)
	10 and later, Server 2016 and later	Current stable version: 133.0 (x64)	2015–
		Old version, yet still maintained: 128.5.0esr (x64)
		Current stable version: 133.0 (IA-32)
		Old version, yet still maintained: 128.5.0esr (IA-32)
	7, Server 2008 R2, 8, Server 2012, 8.1 and Server 2012 R2	Old version, yet still maintained: 115.18.0esr (x64)	2015–2025
		Old version, yet still maintained: 115.18.0esr (IA-32)	2009–2025
	XP, Server 2003, Vista and Server 2008	Old version, no longer maintained: 52.9.0esr (IA-32)	2004–2018
	2000	Old version, no longer maintained: 10.0.12esr	2004–2013
		Old version, no longer maintained: 12.0	2004–2012
	NT 4.0 (IA-32), 98 and Me	Old version, no longer maintained: 2.0.0.20	2004–2008
	95	Old version, no longer maintained: 1.5.0.12	2004–2007
macOS	11 (ARM64) and later	Current stable version: 133.0	2020–
		Old version, yet still maintained: 128.5.0esr
	10.15 (x64) and later	Current stable version: 133.0	2019–
		Old version, yet still maintained: 128.5.0esr
	10.12–10.14	Old version, yet still maintained: 115.18.0esr	2016–2025
	10.9–10.11	Old version, no longer maintained: 78.15.0esr	2013–2021
	10.6–10.8	Old version, no longer maintained: 45.9.0esr	2009–2017
		Old version, no longer maintained: 48.0.2	2009–2016
	10.5 (IA-32 and x64)	Old version, no longer maintained: 10.0.12esr	2007–2013
		Old version, no longer maintained: 16.0.2	2007–2012
	10.4 (IA-32 and PPC)–10.5 (PPC)	Old version, no longer maintained: 3.6.28	2005–2012
	10.2–10.3	Old version, no longer maintained: 2.0.0.20	2004–2008
	10.0–10.1	Old version, no longer maintained: 1.0.8	2004–2006
Linux (X11/Wayland)		Current stable version: 133.0 (x64)	2011–
		Old version, yet still maintained: 128.5.0esr (x64)
		Current stable version: 133.0 (IA-32)	2004–
		Old version, yet still maintained: 128.5.0esr (IA-32)

Legend:

Old version, not maintained

Old version, still maintained

Latest version

Latest preview version

Future release

Notes

• In March 2014, the Windows Store app version of Firefox was cancelled, although there is a beta release.
• SSE2 instruction set support is required for 49.0 or later for Windows and 53.0 or later for Linux, IA-32 support only applies to superscalar processors.
• The x64 build for Windows (introduced with Firefox 43) was exclusive to Windows 7 and later. All previous versions of Windows have to use the IA-32 build.

Operating system		Latest stable version	Support status
Android (including Android-x86)	5.0 and later	Current stable version: 133.0 (x64)	2018–
		Current stable version: 133.0 (ARM64)	2017–
		Current stable version: 133.0 (IA-32)	2014–
		Current stable version: 133.0 (ARMv7)
	4.1–4.4	Old version, no longer maintained: 68.11.0 (x64)	2018–2020
		Old version, no longer maintained: 68.11.0 (IA-32)	2013–2020
		Old version, no longer maintained: 68.11.0 (ARMv7)	2012–2020
	4.0	Old version, no longer maintained: 55.0.2 (IA-32)	2013–2017
		Old version, no longer maintained: 55.0.2 (ARMv7)	2011–2017
	3.0–3.2	Old version, no longer maintained: 45.0.2 (ARMv7)	2011–2016
	2.3	Old version, no longer maintained: 47.0 (ARMv7)
	2.2–4.3	Old version, no longer maintained: 31.3.0esr (ARMv6)	2012–2015
	2.2	Old version, no longer maintained: 31.0 (ARMv7)	2011–2014
	2.1	Old version, no longer maintained: 19.0.2 (ARMv6)	2012–2013
		Old version, no longer maintained: 19.0.2 (ARMv7)	2011–2013
	2.0	Old version, no longer maintained: 6.0.2 (ARMv7)	2011
Firefox OS	2.2	Old version, no longer maintained: 35/36/37	2015
	2.1	Old version, no longer maintained: 33/34	2014–2015
	2.0	Old version, no longer maintained: 31/32
	1.4	Old version, no longer maintained: 30	2014
	1.3	Old version, no longer maintained: 28
	1.2	Old version, no longer maintained: 26	2013
	1.1	Old version, no longer maintained: 18
Maemo		Old version, no longer maintained: 7.0.1	2010–2011
Windows Mobile	6.x	Old version, no longer maintained: 1.0a3	N/A

Legend:

Old version, not maintained

Old version, still maintained

Latest version

Latest preview version

Future release

Notes

• Firefox for iOS is not listed in this table as its version numbers would be misleading. Prior to version 96 it used version numbers that do not correspond to any of the other Firefox versions. Those share a core component, the Gecko rendering engine, and track its version numbers, whereas the version for the iOS operating system uses the operating system's rendering engine (WebKit), rather than Mozilla's (Gecko).

Operating system			Latest stable version	Support status
Solaris	11		Old version, yet still maintained: 128.5.0esr (x64, SPARC V9)	2011–
	10 and OpenSolaris		Old version, no longer maintained: 52.9.0esr (IA-32, x64, SPARC V9)	2005–2018
	8–9		Old version, no longer maintained: 2.0.0.20 (IA-32, SPARC V9)	2004–2008
AIX	7.1 and 7.2		Old version, no longer maintained: 3.6.25 (POWER)	N/A
HP-UX	11i v2–v3		Old version, no longer maintained: 3.5.9 (IA-64, PA-RISC)	N/A
FreeBSD (Tier 1)	13 and later		Current stable version: 133.0 (x64, ARM64)	2021–
			Old version, yet still maintained: 128.5.0esr (x64, ARM64)
	12		Old version, no longer maintained: 121.0 (IA-32)	2018–2024
			Old version, no longer maintained: 115.6.0esr (IA-32)
OpenBSD	-stable	7.6	Current stable version: 133.0 (x64, ARM64, RISC-V)	2024–
			Old version, yet still maintained: 128.5.0esr (x64, ARM64, RISC-V)
		6.9	Old version, no longer maintained: 88.0.1 (IA-32)	2021
			Old version, no longer maintained: 78.14.0esr (IA-32)
		5.8	Old version, no longer maintained: 38.7.1esr (PPC)	2015–2016
		5.7	Old version, no longer maintained: 31.6.0esr (SPARC V9)	2015
		4.7	Old version, no longer maintained: 3.5.10 (Alpha)	2010
	-release	5.8	Old version, no longer maintained: 39.0.3 (PPC)	N/A
		5.4	Old version, no longer maintained: 3.6.28 (Alpha)
		4.7	Old version, no longer maintained: 3.0.18 (ARM)

Legend:

Old version, not maintained

Old version, still maintained

Latest version

Latest preview version

Future release

See also

• GNU IceCat
• History of free and open-source software
• History of Mozilla Application Suite
• Mozilla Corporation software rebranded by the Debian project

Further reading

• Eich, Brendan (2005). Branch Plan. In Mozilla Wiki. Retrieved December 21, 2005.

External links

• Mozilla Firefox release notes for each version
• Mozilla Firefox developer release notes for each version
• Releases - MozillaWiki
• unofficial changelogs for Firefox releases, Jesse Ruderman (last updated in 2008)
• history of the Mozilla logo by Jamie Zawinski
• ben. "Where Did Firefox Come From?". MozillaZine. Archived from the original on July 17, 2011.
• Firefox browser for web 2.0 age, BBC News

[[Category:Firefox]] [[Category:History of free and open-source software|Firefox]] [[Category:History of web browsers|Firefox]] [[Category:Software version histories|Firefox]]