Wikipedia:External links

Wikipedia articles may include links to web pages outside Wikipedia (external links), but they should not normally be used in the body of an article. All external links must conform to certain formatting restrictions. Some acceptable links include those that contain further research that is accurate and on-topic, information that could not be added to the article for reasons such as copyright or amount of detail, or other meaningful, relevant content that is not suitable for inclusion in an article for reasons unrelated to its accuracy.

Some external links are welcome (see "What should be linked", below), but it is not Wikipedia's purpose to include a lengthy or comprehensive list of external links related to each topic. No page should be linked from a Wikipedia article unless its inclusion is justifiable according to this guideline and common sense. The burden of providing this justification is on the person who wants to include an external link.

This guideline concerns external links that are not citations to sources supporting article content. If the website or page to which you want to link includes information that is not yet a part of the article, consider using it as a source for the article, and citing it. Guidelines for sourcing, which includes external links used as citations, are discussed at Wikipedia:Reliable sources and Wikipedia:Citing sources.

Important points to remember

1. This guideline does not apply to inline citations or general references, which should appear in the "References" or "Notes" section.
2. External links should not normally be used in the body of an article. Instead, include appropriate external links in an "External links" section at the end of the article, and in the appropriate location within an infobox, if applicable.
3. Links in the "External links" section should be kept to a minimum. A lack of external links or a small number of external links is not a reason to add external links.
4. In the "External links" section, try to avoid separate links to multiple pages in the same website; instead, try to find an appropriate linking page within the site.
5. This guideline does not apply to links to non-English Wikipedia articles; they are added after External links according to Wikipedia:Layout.

Restrictions on linking

For policy or technical reasons, editors are restricted from linking to the following, without exception:

1. Material that violates the copyrights of others per contributors' rights and obligations should not be linked. Linking to websites that display copyrighted works is acceptable as long as the website has licensed the work. Knowingly directing others to material that violates copyright may be considered contributory copyright infringement. If you know that an external website is carrying a work in violation of the work's copyright, do not link to that copy of the work. Linking to a page that illegally distributes someone else's work casts a bad light on Wikipedia and its editors. This is particularly relevant when linking to sites such as YouTube, where due care should be taken to avoid linking to material that violates copyright.
2. Sites that match the Wikipedia-specific or multi-site blacklist without being whitelisted. MediaWiki's code will automatically block any edits that contain such links.

What to link

There are several things that should be considered when adding an external link.

• Is the site content accessible to the reader?
• Is the site content proper in the context of the article (useful, tasteful, informative, factual, etc.)?
• Is the link functional and likely to remain functional?

Each link should be considered on its merits, using the following guidelines. As the number of external links in an article grows longer, assessment should become stricter. When in doubt about the appropriateness of adding new links, make a suggestion on the article's talkpage and discuss with other editors.

What can normally be linked

1. Wikipedia articles about any organization, person, website, or other entity should link to the subject's official site, if any. See Official links below.
2. An article about a book, a musical score, or some other media should link to a site hosting a copy of the work, if none of the "Links normally to be avoided" criteria apply.
3. Sites that contain neutral and accurate material that is relevant to an encyclopedic understanding of the subject and cannot be integrated into the Wikipedia article due to copyright issues, amount of detail (such as professional athlete statistics, movie or television credits, interview transcripts, or online textbooks), or other reasons.

Links to be considered

1. The recommendation to consider professional reviews as external links was repealed. The reviews should instead be used as sources in a "Reception" section.
2. Very large pages, such as pages containing rich media files, should be considered on a case-by-case basis. Worldwide, many use Wikipedia with a low-speed connection. Unusually large pages should be annotated as such.
3. A well-chosen link to a directory of websites or organizations. Long lists of links are not acceptable. A directory link may be a permanent link or a temporary measure put in place while external links are being discussed on the article's talk page. The Open Directory Project is often a neutral candidate, and may be added using the {{dmoz}} template.
4. Sites that fail to meet criteria for reliable sources yet still contain information about the subject of the article from knowledgeable sources.

Links normally to be avoided

Except for a link to an official page of the article's subject, one should generally avoid:

1. Any site that does not provide a unique resource beyond what the article would contain if it became a featured article.
2. Any site that misleads the reader by use of factually inaccurate material or unverifiable research, except to a limited extent in articles about the viewpoints that the site is presenting.
3. Sites containing malware, malicious scripts, trojan exploits, or content that is illegal to access in the state of Florida.
4. Links mainly intended to promote a website, including online petitions. See external link spamming.
5. Links to individual web pages that primarily exist to sell products or services, or to web pages with objectionable amounts of advertising. For example, the mobile phone article does not link to web pages that mostly promote or advertise cell-phone products or services.
6. Links to sites that require payment or registration to view the relevant content, unless the site itself is the subject of the article, or the link is a convenience link to a citation. See below.
7. Sites that are inaccessible to a substantial number of users, such as sites that only work with a specific browser or in a specific country.
8. Direct links to documents that require external applications or plugins (such as Flash or Java) to view the content, unless the article is about such file formats. See rich media for more details.
9. Links to any search results pages, such as links to individual website searches, search engines, search aggregators, or RSS feeds.
10. Links to social networking sites (such as Myspace and Facebook), chat or discussion forums/groups (such as Yahoo! Groups), Twitter feeds, Usenet newsgroups or e-mail lists.
11. Links to blogs, personal web pages and most fansites, except those written by a recognized authority. (This exception for blogs, etc, controlled by recognized authorities is meant to be very limited; as a minimum standard, recognized authorities always meet Wikipedia's notability criteria for people.)
12. Links to open wikis, except those with a substantial history of stability and a substantial number of editors. Mirrors or forks of Wikipedia should not be linked.
13. Sites that are only indirectly related to the article's subject: the link should be directly related to the subject of the article. A general site that has information about a variety of subjects should usually not be linked to from an article on a more specific subject. Similarly, a website on a specific subject should usually not be linked from an article about a general subject. If a section of a general website is devoted to the subject of the article, and meets the other criteria for linking, then that part of the site could be deep linked.
14. Lists of links to manufacturers, suppliers or customers.
15. Links to sites already linked through Wikipedia sourcing tools. For example, instead of linking to a commercial book site, consider the "ISBN" linking format, which gives readers an opportunity to search a wide variety of free and non-free book sources. Wikipedia:Map sources can be linked by using geographical coordinates.
16. Links that are not reliably functional, or likely to continue being functional. For example, links to temporary internet content, where the link is unlikely to remain operable for a useful amount of time.
17. Affiliate, tracking or referral links i.e. links that contain information about who is to be credited for readers that follow the link. If the source itself is helpful, use a neutral link without the tracking information.
18. External links on Wikipedia navigation pages such as disambiguation, redirect and category pages.
19. Links to websites of organizations mentioned in an article—unless they otherwise qualify as something that should be linked or considered.
20. External links as sole entries in stand-alone lists and embedded lists.

Advertising and conflicts of interest

Main pages: Wikipedia:Conflict of interest and Wikipedia:Spam

It is true that a link from Wikipedia to an external site may drive Web traffic to that site. But in line with Wikipedia policies, you should avoid linking to a site that you own, maintain, or represent—even if WP guidelines seem to imply that it may otherwise be linked. When in doubt, you may go to the talk page and let another editor decide. This suggestion is in line with WP's conflict-of-interest guidelines.

Wikipedia uses the same standards for evaluating links to websites owned by for-profit and (real or purported) non-profit organizations. Links to potentially revenue-generating web pages are not prohibited, even though the website owner might earn money through advertisements, sales, or (in the case of non-profit organizations) donations. Choose which pages to link based on the immediate benefit to Wikipedia readers that click on the link, not based on the organization's tax status or your guess at whether the website's owner might earn money from the link.

A few parties now appear to have a spambot capable of spamming wikis from several different wiki engines, analogous to the submitter scripts for guestbooks and blogs. If you see a bot inserting external links, please consider checking the other language wikis to see if the attack is widespread. If it is, please report it on Meta; they can put in a Wikimedia-wide text filter. Sysops will block unauthorized bots on sight.

In biographies of living people

Main page: Wikipedia:Biographies of living persons

In biographies of living people, material available solely in questionable sources or sources of dubious value should be handled with caution, and, if derogatory, should not be used at all, either as sources or via external links. External links in biographies of living persons must be of high quality and are judged by a higher standard than for other articles. Do not link to websites that are not fully compliant with this guideline or that contradict the spirit of WP:BLP.

Sites requiring registration

Outside of citations, external links to websites that require registration or a paid subscription to view should be avoided because they are of limited use to most readers. Facebook and many online newspapers require registration to access some or all of their content, while some require a subscription. Online magazines frequently require subscriptions to access their sites or for premium content. If old newspaper and magazine articles are archived, there may be a fee for accessing them.

A site that requires registration or a subscription should not be linked unless the website itself is the topic of the article (see Official links below) or the link is part of an inline reference (see Wikipedia:Citing sources). References should be to the most authoritative source, adding a link to a free version if one is available.

Non-English-language content

Outside of citations, external links to English-language content are strongly preferred in the English-language Wikipedia. It may be appropriate to have a link to a non-English-language site, such as when an official site is unavailable in English; or when the link is to the subject's text in its original language; or when the site contains visual aids such as maps, diagrams, or tables—per the guideline on non-English-language sites.

When linking to a site in a non-English language under the exceptions above, label the link with a language icon, available for most languages, using two-letter language codes: for example, {{es icon}}, {{fr icon}}, etc. Place the language label after the link (i.e. [http://de.wikipedia.org/ German Wikipedia] {{de icon}}).

Note that this guideline does not apply to references, which can be in any language, though English is preferred if available and equally reliable. See Wikipedia:Verifiability#Non-English sources for Wikipedia's standards for published sources that are not written in English.

Redirection sites

URL redirection sites are not to be used. Examples of these sites include tinyurl.com, tiny.cc and the .tk top level domain. Most of these sites are listed in the m:Spam blacklist because they are frequently abused by link spammers, which means that it is not possible to save a page that contains such a link. Because URL redirection sites are added to the blacklist whenever abuse occurs, you may create problems for future editors by using them. Adding links to web proxies is prohibited for a similar reason. Instead, one should add a link to the original URL.

It is generally preferred to link to the exact destination of a link. For instance, if example.com is an automatic redirect to tripod.com/example, it is better to link to the exact page, even if the webmaster considers the redirect address to be more official.

Rich media

It is acceptable to link to pages rendered in normal HTML or plain text, but this is not always the case with pages using rich media formats (which may be incompatible with many users' settings and browsers). Check that the content type of the linked page is "text/html", "text/plain", or "application/xhtml+xml" (or another XHTML content type) as some pages may instead be rendered solely by platform-dependent plugins. Try to avoid directly linking to any content that requires special software, or an add-on to a browser. It is always preferred to link to a page rendered in normal HTML that contains embedded links to the rich media.

Where a link to rich media is deemed appropriate, either as a direct link or embedded within an HTML page, an explicit indication of the technology needed to access the relevant content must be given, as in the following examples:

• Interview (along with Lenny Kaye) November 11, 2005 on KEXP-FM; 53 minutes, includes three songs. (Windows Media Player, RealPlayer).
• Berkowitz, Joel, Avrom Goldfaden and the Modern Yiddish Theater: The Bard of Old Constantine (PDF), Pakn Treger, no. 44, Winter 2004, 10–19.

Linking to user-submitted video sites

There is no blanket ban on linking to YouTube or other user-submitted video sites, as long as the links abide by the guidelines on this page (see Restrictions on linking and Links normally to be avoided). Many videos hosted on YouTube or similar sites do not meet the standards for inclusion in External links sections, and copyright is of particular concern. Many YouTube videos of newscasts, shows or other content of interest to Wikipedia visitors are copyright violations and should not be linked to. Links should be evaluated for inclusion with due care on a case-by-case basis. Links to online videos should also identify the software necessary for readers to view the content. For example, all links to YouTube videos should, if applicable, indicate that Flash Video software or a web browser supporting H.264/MPEG-4 AVC is necessary to see the content.

Avoid undue weight on particular points of view

On articles with multiple points of view, avoid providing links too great in number or weight to one point of view, or that give undue weight to minority views. Add comments to these links informing the reader of their point of view. If one point of view dominates informed opinion, that should be represented first. For more information, see Wikipedia:Neutral point of view—in particular, Wikipedia's guidelines on undue weight.

Official links

An official link is a link to a website or other Internet service that meets both of the following:

1. The linked content is controlled by the subject (organization or individual person) of the Wikipedia article.
2. The linked content primarily covers the area for which the subject of the article is notable.

Official links (if any) are provided to give the reader the opportunity to see what the subject says about itself. These links are exempt from the links normally to be avoided, but they are not exempt from the restrictions on linking. For example, although links to websites that require readers to register or pay to view content are normally not acceptable in the External links section, such a link may be included when it is an official website for the subject.

Official links are still subject to standard formatting requirements, such as rich media labeling and not placing links in the text of the article. When an official website is used as a source to verify a self-published statement in the article text, it should be formatted like any other reference used in the article. Official websites may be included in some infoboxes, and by convention are listed first in the External links section. Use of the template {{official website}} is optional.

No official link exists for many articles. "Fansites", including everything from websites run by fans of a musician to a charitable organization supporting patients with a disease, even if they are endorsed or authorized by the subject, are not considered official websites because the subject of the article is unable to control the information being presented. Links to websites that are not considered official websites may still be justifiable under other sections of this guideline, e.g., Links to consider #4.

Minimize the number of links

If the subject of the article has more than one official website, then more than one link may be appropriate. However, Wikipedia does not provide a comprehensive web directory to every official website. Wikipedia does not attempt to document or provide links to every part of the subject's web presence or provide readers with a handy list of all social networking sites. Complete directories lead to clutter and to placing undue emphasis on what the subject says.

More than one official link should be provided only when the additional links provide the reader with unique content and are not prominently linked from other official websites. For example, if the main page of the official website for an author contains a link to the author's blog and Twitter feed, then it is not appropriate to provide links to all three. Instead, provide only the main page of the official website in this situation. In other situations, it may be appropriate to provide more than one link, such as when a business has one website for the corporate headquarters and another for consumer information. Choose the minimum number of links that provide readers with the maximum amount of information. Links that provide consistent information are strongly preferred to social networking and communication services where the content changes rapidly and may not comply with this guideline at any given moment in time.

Longevity of links

It is very important to consider whether the link is likely to remain relevant and acceptable to the article in the foreseeable future. For example, it is not useful to link to a webpage that changes often and merely happens to have a relevant picture or article on its front page at the moment. Consider locating and linking to "permalink" versions of web content, and trying to find resources which have a commitment to keeping content available at the same address.

What can be done with a dead external link

See also: Wikipedia:Link rot

Links to dead URLs in a list of external links are of no use to Wikipedia articles. Such dead links should either be updated or removed. Note however, that the matter is different for references: see Wikipedia:Citing sources#Preventing and repairing dead links.

Note that some dead links are caused by vandalism (for example, a vandal disabling links to products competing with the vandal's favored product): it is worth checking to see if there is a working version of the link in an earlier version of article. Some vandalism of this type is quite subtle, such as replacing ASCII letters in the URL with identical-looking Cyrillic letters.

Hijacked and re-registered sites

URLs can be "hijacked" or re-registered for a different purpose after a registration expires. While the URL remains valid, it no longer points to the desired information, so it needs to be handled as a dead link.

How to link

See also: Help:URL

Link with no text (code and example output):

[http://example.com/]

[2]

Link containing text:

[http://example.com/ The RFC-mandated example.com website]

The RFC-mandated example.com website

All text following a space is taken as the text to use for the link. Embedding wikilinks into the link text is incorrect; instead choose the appropriate words to link.

"The [[RFC]]-mandated [http://example.com/ example.com website]". 

"The RFC-mandated example.com website".

If there are no meaningful words that can be used for the link, a link with no text is preferred to using self-referential link text, such as "click here" or "this link". These types of self-references should be avoided.

The URL must begin with http:// or another internet protocol, such as ftp:// or news://.

External links section

If an article has external links, the standard format is to place them in a bulleted list under a primary heading at the end of the article. External links should identify the link and briefly summarize the website's contents and why the website is relevant to the article. The heading should be "External links" (plural) even if only a single link is listed. If several external links are listed and the subject of the article is a living person, organization, web service, or otherwise has an official website, it is normal practice to place the link to that site at the top of the list.

If you link to another website, you should give your reader a good summary of the site's contents, and the reasons why this specific website is relevant to the article in question. If you link to an online article, try to provide as much meaningful article information as possible. For example:

== External links ==
* [http://example.com/link_1 Link 1]
* [http://example.com/link_2 Link 2]

Most external links should present different details from citations. For instance, a concise description of the contents and a clear indication of its source is more important than the actual title of the page, and access dates are not appropriate in the external links section. Because citation templates were not designed for use in the External links section, editors that use citation templates in this section should be careful to ensure the resulting description is appropriate for an external link.

References and citation

See also: Wikipedia:Citing sources and Wikipedia:Spam § Citation_spam

Sites that have been used as sources in the creation of an article should be cited in the article, and linked as references, either in-line or in a references section. Links to these source sites are not "external links" for the purposes of this guideline, and should not normally be duplicated in an external links section. Exceptions—websites that can be both references and external links—include any official sites for the article topic, or websites that are specifically devoted to the topic, contain multiple subpages, and meet the above criteria.

Linking to databases

Further information: Wikipedia:Template messages/Links

When linking to large database-driven sites like the Internet Movie Database, try to use an external link template. If the URL format of the database ever changes, it is sometimes possible to quickly fix all links by rewriting the template.

Maintenance and review

Inappropriate and duplicative links may be deleted by any editor; if the reason for the deletion is not obvious, please explain on the article's talk page.

Templates may help organize a link maintenance project. The {{external links}} template is for providing notice that the list of links may have grown to an inappropriate length or contain inappropriate links. {{Cleanup-spam}} warns of suspected non-compliant links.

Inline templates may be useful for flagging individual links that you want to further discuss on the article's talk page:

• {{Copyvio link}} – to mark links suspected of violating copyrights
• {{Off-topic-inline}} – to mark links that seem off-topic or irrelevant
• {{Dead link}} – to mark links that do not appear to be working

If a page attracts many links or inappropriate links, a note in the external links section such as {{subst:no more links}} may discourage the addition of links.

If a new or unregistered user persists in adding an inappropriate link to one or more pages, please consider leaving a message for User:XLinkBot. This bot will automatically revert listed sites if added by non-autoconfirmed users, but permit other editors to add them. For malware or serious spamming, please read Wikipedia:Spam blacklist and Wikipedia:WikiProject Spam to recommend site-wide blacklisting.

Two maintenance categories list all tagged articles that need attention to remove spam and non-compliant links. They are:

• Category:Wikipedia external links cleanup
• Category:Wikipedia spam cleanup

In March 2010, each of these categories listed almost 2,000 articles that had been tagged for assistance with external links and spam. Any editor can address these concerns by applying the advice on this page. When an article complies with the relevant standards, then any editor may remove the tags.

Searching for external links

Special:Linksearch is a tool for searching for links from Wikipedia articles to sites outside Wikipedia. For example, all Wikipedia pages linking to Yahoo.com

Handling disputes

This guideline describes the most common reasons for including and excluding links. However, the fact that a given link is not actually prohibited by this guideline does not automatically mean that it must or should be linked. Every link provided must be justifiable in the opinion of the editors for an article. Disputes about links can be addressed through the normal dispute-resolution process, particularly at the external links noticeboard.

Disputed links should normally be excluded by default unless and until there is a consensus to include them.

See also

Syntax

• Wikipedia:Manual of Style (linking)
• Wikipedia:Policies and guidelines
• Wikipedia:Video links
• Wikipedia:Writing better articles
• Category:External link file type templates
• Help:Wiki markup#External links
• m:External links

Maintenance coordination

• Wikipedia:External links/Perennial websites – websites editors frequently inquire about
• Wikipedia:Link rot
• Wikipedia:Linking to external harassment
• Wikipedia:Template messages/Cleanup
• WikiProject External links – dedicated to cleaning up overly long lists of external links and having articles conform to Wikipedia's external links guidelines
• WikiProject Spam – voluntary spam-fighting brigade
• Change detection and notification

Other

• Wikipedia:Further reading
• More information about How to become an xray technician