By adding a prefix to anotherproject, internal link style ("prefixed internal link style") can be used tolink to a page of another project. A system of shorthand link labels are used to refer to different projects, in the context of interproject linking, as seen within the actual source text. For example,en: refers to the English Wikipedia. This is seen in[[:en:Apple]], which producesen:Apple, a link to the English Wikipedia article on "Apple".
This is called "interwiki linking". The precise interwiki links used vary slightly for each project, and can be seen atSpecial:Interwiki.
WithinWikimedia, for the purpose of interlanguage links (see below), the project families are Wikipedia, Wiktionary, Wikiquote, Wikibooks and Wikisource. Thus, this applies for a link like en:, de:, etc., from a Wikipedia to another one, from a Wiktionary to another one, from a Wikiquote to another one, from a Wikibooks to another one or from a Wikisource to another one.
Most of the time, interwiki links are handled byWikidata instead, but the manual interwiki link syntax still works and is useful in edge cases.
This list is incomplete. SeeSpecial:Interwiki for a full list of valid interwiki links.
| Project | Long form | Shortcut |
|---|---|---|
| Wikipedia | [[wikipedia:]] | [[w:]] |
| Wiktionary | [[wiktionary:]] | [[wikt:]] |
| Wikinews | [[wikinews:]] | [[n:]] |
| Wikibooks | [[wikibooks:]] | [[b:]] |
| Wikiquote | [[wikiquote:]] | [[q:]] |
| Wikisource | [[wikisource:]] | [[s:]] |
| Wikisource (multilingual pages) | [[oldwikisource:]] | [[s:mul:]] |
| Wikispecies | [[wikispecies:]] | [[species:]] |
| Wikiversity | [[wikiversity:]] | [[v:]] |
| Wikivoyage | [[wikivoyage:]] | [[voy:]] |
| WikimediaFoundation | [[wikimedia:]][[foundation:]] | [[wmf:]] |
| WikimediaCommons | [[commons:]] | [[c:]] |
| WikimediaMeta-Wiki | [[metawiki:]][[metawikimedia:]][[metawikipedia:]][[meta:]] | [[m:]] |
| Wikimedia Incubator | [[incubator:]] | |
| Wikimedia Strategic Planning | [[strategy:]] | |
| MediaWiki | [[mediawikiwiki:]] | [[mw:]] |
| MediaZilla / Bugzilla | [[mediazilla:]][[bugzilla:]] | |
| Phabricator | [[phabricator:]] | [[phab:]] |
| Testwiki | [[testwiki:]] | |
| Wikidata | [[wikidata:]] | [[d:]] |
| Wikifunctions | [[wikifunctions:]] | [[f:]] |
| Wikitech | [[wikitech:]] | |
| Toolforge | [[toolforge:]] |
| International chapters | Shortcut |
|---|---|
| Argentina | [[wmar:]] |
| Australia | [[wmau:]] |
| Bangladesh | [[wmbd:]] |
| Belgium | [[wmbe:]] |
| Brazil | [[wmbr:]] |
| Canada | [[wmca:]] |
| Czech Republic | [[wmcz:]] |
| Denmark | [[wmdk:]] |
| Germany | [[wmde:]] |
| Finland | [[wmfi:]] |
| Hong Kong | [[wmhk:]] |
| Hungary | [[wmhu:]] |
| India | [[wmin:]] |
| Indonesia | [[wmid:]] |
| Israel | [[wmil:]] |
| Italy | [[wmit:]] |
| Netherlands | [[wmnl:]] |
| North Macedonia | [[wmmk:]] |
| Norway | [[wmno:]] |
| Poland | [[wmpl:]] |
| Russia | [[wmru:]] |
| Serbia | [[wmrs:]] |
| Spain | [[wmes:]] |
| Sweden | [[wmse:]] |
| Switzerland | [[wmch:]] |
| Taiwan | [[wmtw:]] |
| Ukraine | [[wmua:]] |
| United Kingdom | [[wmuk:]] |
Thelong forms are sometimes overwritten by namespaces with the same name. For example[[meta:]] prefers to the Project namespace instead on Meta. Theshortcuts should work everywhere.
Theinterwiki map on Meta lists many prefixes, among others,[[wikipedia:]] for the English Wikipedia, working from any Wiki supporting the Meta interwiki map (except for Wikipedias that use it as a project namespace).
The shortcuts have different histories. Wikipedia, Wikiquote etc. point to the English versions via an entry inm:Interwiki map, and are also included inthe standard MediaWiki interwiki table; w, q, b, wikt etc. are used like interlanguage wikilinks to link to the sisterproject in the same language (sow:it:b: is equivalent toWikibooks:it:), and are hardcoded rather than part ofinterwiki map.
Non-Wikimedia interwiki codes have a limitation, that they can only be used through a link. For example, the entry for "John" on Wiktionary, a Wikimedia project, can be accessed by[[wikt:John]] orhttp://meta.wikimedia.org/wiki/wikt:John. However, the latter method does not work for non-Wikimedia wikis. For example, the main page on the Mozilla Wiki can be accessed via[[MozillaWiki:Main Page]], buthttp://meta.wikimedia.org/wiki/MozillaWiki:Main_Page results in an error. In these cases, Special:Search can be used (http://meta.wikimedia.org/wiki/Special:Search/MozillaWiki:Main_Page). You can seethe Interwiki special page for a list of "forward" and "non-forward" prefixes.
A project's namespace prefix cannot be reused as code for an external project. However, the prefix used for a target project may coincide with the prefix for a project namespace, within that project.You can't use one project's namespace prefix in another project's codebase because it might match a namespace within that same project. For example,MediaWiki:Sidebar exists on MetaWiki, Wikibooks, and MediaWiki.So, when you're linking to a page in that namespace, add the project prefix, like this:MetaWiki:MediaWiki:Sidebar,Wikibooks:MediaWiki:Sidebar, orMediawikiwiki:MediaWiki:Sidebar.
When dealing with pages whose title begins with the projects prefix but the page is internal, for exampleWikibooks:What is Wikibooks?, keep things consistent across projects by adding the projects prefix again. It becomes,Wikibooks:Wikibooks:What is Wikibooks?.
In the first example theWikibooks: prefix gets in the way of recognizingWikibooks: as a namespace in Wikibooks. But in MetaWiki, addingWikibooks: makes the link to be treated as an interwiki prefix rather than a namespace, this allows links to be redirected to another project.
Interwiki links can use prefixes for theproject and/or for thelanguage. Without the prefix, links are local, for pages in the same project and the same language. If only a language is given, they go to a page in the same (or similar) project for the specified language. If a language is given on a multilingual wiki, it will go to the Wikipedia of the given language:
[[:fr:]]fr:[[:os:]]os:
If only the project is specified, they typically go to the specified project in the corresponding language of the source, see above. At most, two prefixes are needed for pages in any existing project and any supported language. If a project is given on a multilingual wiki, it will go to the English version of the project:
[[s:de:Hauptseite]]s:de:Hauptseite[[b:en:Main page]] b:en:Main page[[n:en:Main page]] n:en:Main page
If the language is different, specifying it before the project can also work. However, this isdiscouraged, as it may not function as expected on some projects:
[[:de:q:Hauptseite]]de:q:Hauptseite (not recommended)[[:en:n:Main page]] en:n:Main page (not recommended)
More than two prefixes are generally unnecessary, the following examples should work everywhere:
[[m:Help:Help]]m:Help:Help[[w:Interwiki]]w:Interwiki
Two prefixes can have unexpected effects, for example, fromMeta, the following links end up on different pages:
[[m:en:About]] m:en:About[[:en:m:About]]en:m:About[[m:About]] m:About
In the first caseMeta ignores them:, because it is local and then, interpretsen: asw:en:, the prefix for theEnglish Wikipedia. In the second case, the leadingen: goes to the English Wikipedia, where the followingm: goes straight back toMeta.
In other words, multiple prefixes are evaluated left to right by the relevant Wikimedia servers (project and language). For projects without different languages, likeMeta (because Meta ismultilingual by itself), language prefixes can be handled as shorthands forw: plus the specified language:
[[:pl:2006]] pl:2006[[w:pl:2006]] w:pl:2006[[:pl:w:2006]]pl:w:2006
FromMeta, the first two links both arrive at the Polish 2006 page. The third arrives at the EnglishWikipedia, because that's how the server selected by:pl: interprets the second prefixw:.
For a portable link on that server, it would be a bad idea to usew:, but:pl: does the trick. To test that effect fromMeta, the following links should go to the same page:
[[:ja:2006]] ja:2006[[:ja:ja:2006]]ja:ja:2006
A universal interwiki link, that is, one that works no matter from which Wikimedia wiki, can be written [[m:project:language:page name]] (e.g.m:b:nl:Wiskunde); this routes the parsing of the links via Meta (bug 4285).
In short, if you want the links to always work in the same way, always use[[m:Example]] to link to anything on Meta-Wiki; always use[[w:en:Example]] to link to anything on English Wikipedia; always use[[q:de:Beispiel]] to link to anything on German Wikiquote.
Technically, an interwikidefined as local is one which always "forwards" to the destination: such interwikis can always be concatenated. The examples above work because all those interwikis are local in all those wikis. Interwikis which are not local in the wiki where they're concatenated or used directly won't work. The following works:
[[MeatBall:AssumeGoodFaith]] MeatBall:AssumeGoodFaith
All these don't ("Bad title" error):
[[w:MeatBall:AssumeGoodFaith]] w:MeatBall:AssumeGoodFaithhttps://meta.wikimedia.org/wiki/MeatBall:AssumeGoodFaith https://meta.wikimedia.org/wiki/MeatBall:AssumeGoodFaithhttps://en.wikipedia.org/wiki/MeatBall:AssumeGoodFaith https://en.wikipedia.org/wiki/MeatBall:AssumeGoodFaith
Non-local interwiki links will still work if you type them in the search bar and choose "go".
For a multilingual family of similar projects, with one project per language, a system forinterlanguage linking can be set up, setting$wgInterwikiMagic to true and$wgHideInterlanguageLinks to false. If this project is in a family for which this applies,Help:Interlanguage link demo may demonstrate what is explained below (this depends on whether the same language codes are used).
An interwiki link within the family is treated differently, unless it is on a talk page of any namespace. It appears at one or two edges of the webpage (left in Monobook, top and bottom in Classic).
Thus, an interlanguage link is mainly suitable for linking to the most closelycorresponding page in another language. It is not suitable for multiple links of the same other language. SeeInterlanguage use case for a discussion of common troubles with this system and other possible implementations.
The feature can also be used on an image description page, to link to the same or a similar image in a sister project. Other interwiki links to images require the prefixed colon.
Note that, if a page may be used as atemplate (even if it is not in the template namespace), it should note its interlanguage links between<noinclude> and</noinclude>. This is the same idea as forcategories.
Comparison:
For projects likeMeta, a missing leading colon has no effect, because Meta doesn't support interlanguage links. ForWikipedia and similar projects, it is a major difference. The mutual order of interlanguage links is preserved, but otherwise the positions within the wikitext are immaterial, again the same rule as for categories. Usually they are put at the end. With section editing, they appear in the preview, if they are in the section being edited. A link to the project itself (hence, also a link to the page itself), even if referred to with the project prefix, appears in-page.
Suppose that we have pagesde:Zug,en:Train andfr:Train, then we need:
An interlanguage link in the wider sense includes a link to a corresponding page in another language, which, for the software, is a regular link, as opposed to one employing the special interlanguage linkfeature as described above. This can also be an internal link on a multilingual project, e.g. on Meta:
Possible reasons for using an "interlanguage link" in the page body include: