Wikipedia:External links: Difference between revisions

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"WP:EL" redirects here; for information on edit locks, see Wikipedia:Edit lock. For the guideline on citation/reference links, see Wikipedia:Citing sources. For the style guide for interior links, see Wikipedia:Manual of Style (links). For the related WikiProject, see Wikipedia:WikiProject External links.

This page documents an English Wikipedia style guideline.

Editors should generally follow it, though exceptions may apply. Substantive edits to this page should reflect consensus. When in doubt, discuss first on this guideline's talk page.

Shortcuts

This page in a nutshell: Adding external links can be a service to our readers, but they should be kept to a minimum of those that are meritable, accessible and appropriate to the article.

Wikipedia articles may include links to Web pages outside Wikipedia. Such pages could 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 (such as professional athlete statistics, movie or television credits, interview transcripts, or online textbooks); or other meaningful, relevant content that is not suitable for inclusion in an article for reasons unrelated to their reliability (such as reviews and interviews).

Some external links are welcome (see "What should be linked", below), but Wikipedia's purpose is not to include a comprehensive list of external links related to each topic. No page should be linked from a Wikipedia article unless its inclusion is justifiable.

The subject of this guideline is external links that are not citations of article sources. 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

Links 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.
External links should not be used in the body of an article. Instead, include them in an "External links" section at the end or in the appropriate location within an infobox.
Try to avoid linking to multiple pages from the same website; instead, try to find an appropriate linking page within the site.

Restrictions on linking

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

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 infringement. If you know that an external Web site is carrying a work in violation of the creator's copyright, do not link to that copy of the work. Linking to a page that illegally distributes someone else's work sheds 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 its creator's copyright.
Sites that match the spam blacklist without being whitelisted. Wikipedia'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 it accessible to the reader?
Is it proper in the context of the article (useful, tasteful, informative, factual, etc.)?
Is it a functional link, and likely to continue being a functional link?

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 should be linked

Articles about any organization, person, web site, or other entity should link to the official site if any.
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.
Sites that contain neutral and accurate material that 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.
Sites with other meaningful, relevant content that is not suitable for inclusion in an article, such as reviews and interviews.

Links to be considered

For albums, movies, books, and other creative works, links to professional reviews.
Very large pages 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.
Long lists of links are not appropriate: Wikipedia is not a mirror or a repository of links. If you find a long list of links in an article, you can tag the "External links" section with the {{External links}} template. Where editors have not reached consensus on an appropriate list of links, a link to a well chosen web directory category could be used until such consensus can be reached. The Open Directory Project is often a neutral candidate, and may be added using the {{dmoz}} template.
Sites which 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 a page that is the subject of the article or an official page of the article subject—and not prohibited by restrictions on linking—one should avoid:

Any site that does not provide a unique resource beyond what the article would contain if it became a Featured article.
Any site that misleads the reader by use of factually inaccurate material or unverifiable research. See Reliable sources for explanations of the terms "factually inaccurate material" or "unverifiable research".
Any site that attempts to surreptitiously install malware on a visitor's computer.
Links mainly intended to promote a website. See External link spamming.
Links to sites that primarily exist to sell products or services. For example, instead of linking to a commercial bookstore site, use the "ISBN" linking format, giving readers an opportunity to search a wide variety of free and non-free book sources.
Links to sites with objectionable amounts of advertising.
Links to sites that require payment or registration to view the relevant content.
Sites that are inaccessible to a substantial number of users, such as sites that only work with a specific browser.
Direct links to documents that require external applications (such as Flash or Java) to view the relevant content, unless the article is about such rich media. If you do link to such material make a note of what application is required.
Links to search engine and aggregated results pages.
Links to social networking sites (such as MySpace or Fan sites), discussion forums/groups (such as Yahoo! Groups) or USENET.
Links to blogs and personal web pages, except those written by a recognized authority.
Links to open wikis, except those with a substantial history of stability and a substantial number of editors. Wikis that meet this criteria might also be added to Meta:Interwiki map.
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.
Lists of links to manufacturers and suppliers.
Links to sites already linked through Wikipedia sourcing tools, such as Wikipedia:Book sources with ISBNs and Wikipedia:Map sources with geographical coordinates.
Links to temporary internet content, where the link is unlikely to remain operable for a useful amount of time.

Advertising and conflicts of interest

Due to the rising prominence of Wikipedia and the amount of extra traffic it can bring a site, there is a great temptation to use Wikipedia to advertise or promote sites. This includes both commercial and non-commercial sites. You should avoid linking to a website that you own, maintain or represent, even if the guidelines otherwise imply that it should be linked. If the link is to a relevant and informative site that should otherwise be included, please consider mentioning it on the talk page and let neutral and independent Wikipedia editors decide whether to add it. This is in line with the conflict of interest guidelines. Note that since Wikipedia uses nofollow tags, external links may not alter search engine rankings.

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

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 in full compliance with Wikipedia official policies.

Sites requiring registration

Sites that require registration or a paid subscription should be avoided because they are of limited use to most readers. 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 magazines articles are archived, there is usually a fee for accessing them.

A site that requires registration or a subscription should not be linked unless the web site itself is the topic of the article or is being used as an inline reference.

Non-English language content

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}}).

Redirection sites

URL redirection sites are not to be used. Examples of these sites include tinyurl.com and tiny.cc. 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 user's 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.

In an instance where a link to rich media is deemed appropriate, an explicit indication of the technology needed to access the content must be given, as in the following examples:

Interview (along with Lenny Kaye) November 11, 2005 on KEXP; 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 YouTube, Google Video, and similar sites

There is no blanket ban on linking to these sites as long as the links abide by the guidelines on this page (which would be infrequent). See also Wikipedia:Copyrights for the prohibition on linking to pages that violate copyrights.

Avoid undue weight on particular points of view

On articles with multiple points of view, the number of links dedicated to one point of view should not overwhelm the number dedicated to other equal points of view, nor 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.

Longevity of links

It is very important to consider if 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 homepage that changes often and merely happens to have a relevant picture or article on its front page at the moment.

What can be done with a dead external link

Links to dead URLs in a list of external links are of no use to Wikipedia articles. Such dead links should either be removed, or updated with archived versions, which might be found at the Internet Archive Wayback Machine. Note however, that the matter can be quite different when these links are references: see Wikipedia:Citing sources#What to do when a reference link "goes dead".

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

Occasionally a site will either be "hijacked" or be re-registered for a different purpose after a registration expires. In either case, while the URL is still valid it points to a page with different or altered content, which can lead to inappropriate content being linked, including in some cases pornography sites.^[1] Sites that have been hijacked or changed after reregistration should not be linked; they should be handled in the same manner as dead links.

How to link

Link with no text (code and example output):

[http://example.com/]

[1]

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".

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 there is only a single link listed.

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]

References and citation

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 be placed in an external links section. See Wikipedia:Verifiability and Wikipedia:Citing sources for specific formatting and linking guidelines for citations.

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

References

^ "Porn Sites Hijack Expired Domain Names". {{cite web}}: Cite has empty unknown parameter: |1= (help)

[1] "Porn Sites Hijack Expired Domain Names". {{cite web}}: Cite has empty unknown parameter: |1= (help)

[1]

@@ Line 65: / Line 65: @@
 # 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.
 # Lists of links to manufacturers and suppliers.
+# Links to sites already linked through Wikipedia sourcing tools, such as [[Wikipedia:Book sources]] with [[Wikipedia:ISBN|ISBN]]s and [[Wikipedia:Map sources]] with [[Wikipedia:Manual of Style (dates and numbers)#Geographical coordinates|geographical coordinates]].
 # Links to temporary internet content, where the link is unlikely to remain operable for a useful amount of time.