Help:URL Information & Help:URL Links at HealthHaven.com

Like all pages on the World Wide Web, the pages delivered by Wikimedia's servers have URLs to identify them. These are the addresses that appear in your browser's address bar when you view a page. Wikipedia editors also have the ability to create hyperlinks to chosen URLs, pointing to pages either within Wikipedia and other Wikimedia projects, or elsewhere on the Web.

[edit] Linking to URLs

When editing a page, hyperlinks to other pages within Wikipedia (or other Wikimedia projects) are normally made as wikilinks or interwikilinks, using the [[...]] syntax described at Help:Link. However if you want to link to an outside website, or to certain specially generated Wikimedia pages (such as a past version of an article), it is necessary to provide the full URL. This is done using external link syntax.

There are three forms of external link syntax:

If the URL is simply included in the wikitext, without square brackets, then it appears as written, and a hyperlink is created: http://meta.wikimedia.org/ produces http://meta.wikimedia.org/
If the URL is placed in square brackets, then a hyperlink is created with a serial number as its label: [http://meta.wikimedia.org/] gives [1]
If the URL is placed in square brackets followed by a space and some text, then that text is used as the label for the hyperlink: [http://meta.wikimedia.org/ Wikimedia] gives Wikimedia

To suppress the arrow icon, place the external link between <span class="plainlinks">...</span> tags.

The URL given must start with "http://", "https://" or "ftp://".^[1] Moreover it cannot contain spaces, and must consist only of the following characters: A-Z a-z 0-9 ._\/~%-+&#?!=()@:

Normally the desired URL can simply be copied and pasted from the address bar of your browser. If you are constructing the URL yourself for any reason, remember that certain reserved characters need to be percent coded. For example, ^ has to be written %5e, the hexadecimal ASCII value with a percent sign in front. A blank space can also be converted into an underscore.

Higher Unicode characters can be included in URLs (like in internal links); the system will convert them as necessary. For example: http://meta.wikipedia.org/wiki/À_propos_de_Méta is equivalent to http://meta.wikipedia.org/wiki/%C3%80_propos_de_M%C3%A9ta .

For more details on how to make percent codes, see URLs in external links at Meta.

[edit] URLs of Wikipedia pages

English Wikipedia's URLs begin http://en.wikipedia.org/. That address on its own is redirected to the Main Page.

The URL of a Wikipedia page takes one of two forms:

http://en.wikipedia.org/wiki/Page_name (the default, as used by the system)
http://en.wikipedia.org/w/index.php?title=Page_name (an alternative which gives the same result)

The page name may include a namespace prefix (such as "Help:" in this page). With some special pages it may also include a parameter, as in http://en.wikipedia.org/wiki/Special:Contributions/Jimbo_Wales (but for most special page parameters, see below).

Other URLs associated with a page are constructed by adding a query string. The string can be added to either of the above forms (as in http://en.wikipedia.org/wiki/Train?action=history ), but in this case the system defaults to the second form, i.e. it extends the index.php query string "title=Page_name".

Extended URLs are used:

To go to a redirect page without following the redirect: http://en.wikipedia.org/w/index.php?title=Railway_train&redirect=no
To go to the edit page (or view the source of a protected page): http://en.wikipedia.org/w/index.php?title=Train&action=edit. Other parameters can be added, such as section=5 or section=new to edit or add a page section. There are also parameters for preloading text into the edit box of a new page, as used by the inputbox extension (see mw:Extension:InputBox).
To access the edit history of a page: http://en.wikipedia.org/w/index.php?title=Train&action=history (or further parameters can be added, as in http://en.wikipedia.org/w/index.php?title=Train&limit=5&offset=90&action=history, which displays edits 91–95).
To link to a particular version of a page: http://en.wikipedia.org/w/index.php?title=Train&oldid=1374279 (this gives a permanent link to a particular version of the page). A permanent link to the present version of the page can be accessed by clicking "Permanent link" under "toolbox" on the left side of the page. Note that the version ID is unique across all pages, so the title parameter here has no effect, and can in fact be omitted.
To link to a diff between two versions of a page: http://en.wikipedia.org/w/index.php?title=Train&diff=1374279&oldid=1260056 , where diff is the ID of the version to appear on the right. Set diff=0 to compare the current version; set diff=0 and oldid=0 to compare the two most recent versions. Again the title parameter has no real effect (you can in fact compare versions of two different pages).
To watch or unwatch a page: http://en.wikipedia.org/w/index.php?title=Train&action=watch (or action=unwatch).
To purge a page from the server cache (to have it rendered with the latest template versions etc.): http://en.wikipedia.org/w/index.php?title=Train&action=purge (this is not the same as purging your browser cache).
To perform certain other defined actions, replacing purge in the above example with view, delete, revert, rollback, unprotect, info, markpatrolled, validate, render, deletetrackback (most of these are available only to administrators).
To obtain the raw wikitext of a page without downloading the full HTML: http://en.wikipedia.org/w/index.php?title=Train&action=raw
To view a category listing starting from a specified point: http://en.wikipedia.org/w/index.php?title=Category:Disambiguation_pages&from=B
To specify parameters for a special page, as in: http://en.wikipedia.org/w/index.php?/w/index.php?title=Special:Recentchanges&from=20030918220000 (in this case the "from" parameter is a timestamp, format yyyymmddhhmmss, UTC time, but many other types of parameter are possible, depending on the page).

If constructing URLs for Wikipedia pages, remember to convert spaces into underscores, and to percent-code special characters where necessary, as described in the previous section. (For how to do this in template code, see Templates and programming below.)

Various kinds of error message may appear if an invalid URL, or one to which you do not have access, is submitted. In other cases the URL may redirect to a valid one (for example, page titles are converted to their canonical form as they are when they appear in wikilinks).

[edit] URLs on other Wikimedia projects

Other projects use similar URLs to those of English Wikipedia, except that the domain names vary: http://meta.wikimedia.org/ (Meta), http://fr.wikipedia.org/ (French Wikipedia), http://de.wiktionary.org/ (German Wiktionary), etc.

Note that http://www.wikipedia.org leads to an international Wikipedia portal page, but other URLs beginning with that prefix redirect to English Wikipedia.

Other projects may also use different strings in place of "/w/" and "/wiki/" in URLs. For details, see the URL help page on Meta.

[edit] Templates and programming

For use in templates, correct URLs can be constructed using certain magic words and parser functions such as fullurl, urlencode and others. Details of these can be found at mw:Help:Magic words.

Most programmatic interaction with Wikipedia can be performed most efficiently using the API, for which URLs beginning http://en.wikipedia.org/w/api.php are used. For details, see mw:API.

[edit] Notes

^ Note that URLs beginning "file://" do not work. This could be enabled (to work in MSIE only) by adding a $wgUrlProtocols entry to LocalSettings.php; see the $wgUrlProtocols in DefaultSettings.php for examples.

[edit] See also

URL help page at Meta

[0] Note that URLs beginning "file://" do not work. This could be enabled (to work in MSIE only) by adding a $wgUrlProtocols entry to LocalSettings.php; see the $wgUrlProtocols in DefaultSettings.php for examples.

[1]