Wikipedia articles can often be improved by providing links to web pages outside Wikipedia which contain information that can't or shouldn't be added to the article. These links belong in an External links section near the bottom of the article.

Some external links are welcome (see below), but it is not Wikipedia's purpose to include a comprehensive list of external links related to each topic. If the site or page you want to link to includes information that is not yet a part of the article, consider using it as a source first. Refer to the citation guideline for instructions on citing sources. This guideline refers to external links other than citations.

Important points to remember

  1. 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.
  2. Rather than creating a long list of external links, editors should consider linking to a related category in the Open Directory Project (also known as DMOZ) which is devoted to creating relevant directories of links pertaining to various topics. If there is no relevant category, you can request help finding or creating a category by placing ((Directory request)) on the article's talk page.
  3. 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.

  1. A website that you own, maintain or are acting as an agent for; even if the guidelines otherwise imply that it should be linked to. This is in line with the conflict of interests guidelines. If it is a relevant and informative link that should otherwise be included, mention it on the talk page and let neutral and independent Wikipedia editors decide whether to add it.
  2. Sites that violate the copyrights of others per contributors' rights and obligations. Sites which fail to provide licensing information or to respond to requests for licensing information should not be used. Links to sites containing publicly contributed content, such as video upload sites, or photo collections where the copyright status is in doubt, should not be added. Knowingly and intentionally directing others to a site that violates copyright has been considered a form of contributory infringement in the United States.
  3. Sites that match the spam blacklist. Pages that contain links matching the blacklist cannot be saved.

What to link to

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

Each link be considered on its merits, using the following guidelines. As the number of external links in an article grows longer, assessment should become stricter.

What should be linked to

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

Links to be considered

  1. For albums, movies, books, and other creative works, links to professional reviews.
  2. A web directory category, when deemed appropriate by those contributing to the article, with preference to open directories.
  3. 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.

Links normally to be avoided

Except for a link to a page that is the subject of the article or is an official page of the subject of the article, one should avoid:

  1. Any site that does not provide a unique resource beyond what the article would contain once it becomes a Featured article.
  2. Any site that misleads the reader by use of factually inaccurate material or unverifiable research. See Reliable sources.
  3. Links that are added to promote a site, that primarily exist to sell products or services, that have objectionable amounts of advertising, or that require payment to view the relevant content, colloquially known as external link spamming. For example, instead of linking to a book's entry on Amazon.com or another bookstore site, use the "ISBN" linking format, giving readers an opportunity to search a wide variety of free and non-free book sources.
  4. Sites that are inaccessible to a substantial number of users, such as sites that only work with a specific browser.
  5. 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.
  6. Links to search engine results pages.
  7. Links to social networking sites (such as MySpace), or discussion forums.
  8. Links to blogs, except those written by a recognized authority.
  9. Links to wikis, except those with a substantial history of stability and a substantial numbers of editors.
  10. Sites that are only indirectly related to the article's subject: it should be a simple exercise to show how the link is directly and symmetrically related to the articles subject. This means that there is both a relation from the website to the subject of the article, and a relation from the subject of the article to the website. For example, the officially sanctioned online site of a rock band has a direct and symmetric relationship to that rock band, and thus should be linked to from the rock band's Wikipedia article. An alternative site run by fans is not symmetrically related to the rock band, as the rock band has only indirect connections with that site.

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 to unless:

Foreign language links

English language links are strongly preferred in the English-language Wikipedia. It may be appropriate to have a link to a foreign language site, such as when an official site is unavailable in English, when the link is to the subject's text in its original language or they contain visual aids such as maps, diagrams, or tables, per the guideline on foreign-language sites.

When linking to a site in a foreign 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.

Redirection sites

Do not use URL redirection sites in external links. Such sites include tinyurl.com and makeashorterlink.com. 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. Since URL redirection sites are added to the blacklist whenever abuse occurs, you may create problems for future editors by using them.

Permanent URL sites, like purl.org, may be a different case, as sometimes the PURL version is considered by the site owner to be a more official URL than the direct URL — in that case, the PURL should be used.

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. Check that the content type of page linked to is "text/html", "text/plain", or "application/xhtml+xml" as some pages may instead be rendered solely by platform dependant plugins. 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:

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. Similarly, be wary of citing an unstable page as a source.

What can be done with a dead external link

See also: Wikipedia:Dead external links

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 may 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 sites

Occasionally a site will be "hijacked", and while the URL is still valid it points to a page with different or altered content. One common cause of this has been the site's domain name expiring and being bought out for a different purpose. This can lead to highly inappropriate content being linked to, including in some cases pornography sites.[1] Sites which have been hijacked should not be linked to, and handled in the same manner as dead links.

How to link

Link with no text (code and example output):



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

There are two basic formats for external links. The most common is to add a list of external links at the end of an article. Put here, in list form, any web sites that you have used or recommend for readers of the article. The standard format for these is to have a level 2 header (i.e. == Header ==) named "External links" followed by a bullet list of links.

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 cite an online article, try to provide as much meaningful citation information as possible.

=== 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 references in the creation of an article should be linked to in a references section, not an external links section. See Wikipedia:Verifiability and Wikipedia:Citing sources for specific formatting and linking guidelines for citations.

See also

For more detailed information regarding Wikipedia policy toward and appropriate syntax for external links, see:

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