URL — Mediated Wiki

{{short description |Address on the World Wide Web}} {{pp-semi-indef}} {{other uses}} {{Use dmy dates|date=May 2020|cs1-dates=y}} {{Infobox technology standard | title = URL | long_name = Uniform resource locator | native_name = | native_name_lang = | image = | caption = | status = Published | year_started = | version = [https://url.spec.whatwg.org Living Standard] | version_date = 2023 | preview = | preview_date = | organization = Internet Engineering Task Force (IETF) | committee = Web Hypertext Application Technology Working Group (WHATWG) | base_standards = {{Plainlist| * {{Sum RFC|3986|ref=yes}}  * {{Sum RFC|4248|ref=yes|status=no}} * {{Sum RFC|4266|ref=yes|status=no}} * {{Sum RFC|6068|ref=yes|status=no}} * {{Sum RFC|6270|ref=yes|status=no}} }} | related_standards =URI, URN | abbreviation = URL | domain = World Wide Web | license = [https://creativecommons.org/licenses/by/4.0/ CC BY 4.0] | website = {{URL|https://url.spec.whatwg.org}} |first_published = {{Start date and age|1994}}|authors=Tim Berners-Lee|series=Request for Comments (RFC)|editors=Anne van Kesteren}} A '''uniform resource locator''' ('''URL'''), colloquially known as a '''web address''',{{sfnp|W3C|2009}} is a reference to a resource on the World Wide Web. A URL specifies the location of a resource on a computer network and a mechanism for retrieving it. A URL is a specific type of Uniform Resource Identifier (URI),<ref>{{Cite web |url=https://zzz.buzz/2017/09/19/forward-and-backslashes-in-urls/ |title=Forward and Backslashes in URLs |website=zzz.buzz |access-date=19 September 2018 |archive-date=2018-09-04 |archive-url=https://web.archive.org/web/20180904050005/https://zzz.buzz/2017/09/19/forward-and-backslashes-in-urls/ |url-status=live }}</ref>{{Ref RFC|3986}} although many people use the two terms interchangeably.{{Ref RFC|3305}}{{efn|A URL implies the means to access an indicated resource and is denoted by a protocol or an access mechanism, which is not true of every URI.{{Ref RFC|3986}}{{Ref RFC|3305}} Thus <code><nowiki>http:</nowiki>//www.example.com</code> is a URL, while <code>www.example.com</code> is not.<ref>{{Cite web |url=https://danielmiessler.com/study/url-uri/#gs.Hs64zOs |title=The Difference Between URLs and URIs |author-last=Miessler |author-first=Daniel |access-date=2017-03-16 |archive-date=2017-03-17 |archive-url=https://web.archive.org/web/20170317054341/https://danielmiessler.com/study/url-uri/#gs.Hs64zOs |url-status=live }}</ref>}} A URL is most commonly used to reference a web page (HTTP/HTTPS) but is also used for file transfer (FTP), email (mailto), database access (JDBC), and many other applications.

Most web browsers display the URL of a web page above the page in an address bar. As an example of a web page URL, <code><nowiki>https://www.example.com/index.html</nowiki></code> indicates protocol <code>https</code>, hostname <code>www.example.com</code>, and file name <code>index.html</code>.

==History== The Uniform Resource Locator was defined in {{Sum RFC|1738|title=no|ref=yes}} in 1994 by Tim Berners-Lee, the inventor of the World Wide Web, and the URI working group of the Internet Engineering Task Force (IETF),{{sfnp|W3C|1994}} as an outcome of collaboration started at the IETF Living Documents birds of a feather session in 1992.{{sfnp|W3C|1994}}{{sfnp|IETF|1992}}

The format combines the pre-existing system of domain names (created in 1985) with file path syntax, where slashes are used to separate directory and filenames. Conventions already existed where server names could be prefixed to complete file paths, preceded by a double slash (<code>//</code>).{{sfnp|Berners-Lee|2015}}

Berners-Lee later expressed regret at the use of dots to separate the parts of the domain name within URIs, wishing he had used slashes throughout,{{sfnp|Berners-Lee|2015}} and also said that, given the colon following the first component of a URI, the two slashes before the domain name were unnecessary.{{sfnp|BBC News|2009}}

Early WorldWideWeb collaborators, including Berners-Lee, originally proposed the use of UDIs: Universal Document Identifiers. An early (1993) draft of the HTML Specification<ref>{{cite tech report |title=Hypertext Markup Language (draft RFCxxx) |author-first1=Tim |author-last1=Berners-Lee |author-link1=Tim Berners-Lee |author-first2=Daniel "Dan" |author-last2=Connolly |author-link2=Daniel Connolly |date=March 1993 |page=28 |url=https://www.ucc.ie/archive/curia/dtds/html-spec.ps |access-date=2017-10-23 |archive-date=2017-10-23 |archive-url=https://web.archive.org/web/20171023232709/https://www.ucc.ie/archive/curia/dtds/html-spec.ps |url-status=live }}</ref> referred to "Universal" Resource Locators. This was dropped some time between June 1994{{Ref RFC|1630}} and October 1994.<ref>{{cite tech report |title=Uniform Resource Locators (URL) |author-first1=Tim |author-last1=Berners-Lee |author-link1=Tim Berners-Lee |author-first2=Larry |author-last2=Masinter |author-link2=Larry Masinter |author-first3=Mark Perry |author-last3=McCahill |author-link3=Mark Perry McCahill |date=October 1994 |url=http://ds.internic.net/internet-drafts/draft-ietf-uri-url-08.txt}} (This Internet-Draft was published later that year as RFC 1738) Cited in {{cite tech report |title=Constituent Component Interface++ |author-first1=C. S. |author-last1=Ang |author-first2=D. C. |author-last2=Martin |publisher=UCSF Library and Center for Knowledge Management |date=January 1995 |url=https://listserv.heanet.ie/cgi-bin/wa?A2=ind9501&L=HTML-WG&P=R23201&X=C6F9505B05BC9A3B67 |access-date=2017-10-23 |archive-date=2017-10-23 |archive-url=https://web.archive.org/web/20171023231159/https://listserv.heanet.ie/cgi-bin/wa?A2=ind9501&L=HTML-WG&P=R23201&X=C6F9505B05BC9A3B67 |url-status=live }}</ref> In his book ''Weaving the Web'', Berners-Lee emphasizes his preference for the original inclusion of "universal" in the expansion rather than the word "uniform", to which it was later changed, and he gives a brief account of the contention that led to the change.

==<span class="anchor" id="syntax"></span>Syntax== {{main|Uniform Resource Identifier#Syntax}} {{Transcluded section|Uniform Resource Identifier|syntax|part=yes}}

Every HTTP URL conforms to the syntax of a generic URI. {{#section:Uniform resource identifier|syntax}}

A web browser will usually dereference a URL by performing an HTTP request to the specified host, by default on port number 80. URLs using the <code>https</code> scheme require that requests and responses be made over a secure connection to the website.

==Internationalized URL== Internet users are distributed throughout the world using a wide variety of languages and alphabets, and expect to be able to create URLs in their own local alphabets. An Internationalized Resource Identifier (IRI) is a form of URL that includes Unicode characters. All modern browsers support IRIs. The parts of the URL requiring special treatment for different alphabets are the domain name and path.{{sfnp|W3C|2008}}{{sfnp|W3C|2014}}

The domain name in the IRI is known as an Internationalized Domain Name (IDN). Web and Internet software automatically convert the domain name into punycode usable by the Domain Name System; for example, the Chinese URL <code><nowiki>http:</nowiki>//例子.卷筒纸</code> becomes <code><nowiki>http:</nowiki>//xn--fsqu00a.xn--3lr804guic/</code>. The <code>xn--</code> indicates that the character was not originally ASCII.{{sfnp|IANA|2003}}

The URL path name can also be specified by the user in the local writing system. If not already encoded, it is converted to UTF-8, and any characters not part of the basic URL character set are escaped as hexadecimal using percent-encoding; for example, the Japanese URL <code><nowiki> http:</nowiki>//example.com/引き割り.html</code> becomes <code><nowiki>http:</nowiki>//example.com/%E5%BC%95%E3%81%8D%E5%89%B2%E3%82%8A.html</code>. The target computer decodes the address and displays the page.{{sfnp|W3C|2008}}

==Protocol-relative URLs<span class="anchor" id="prurl"></span>==  Protocol-relative links (PRL), also known as protocol-relative URLs (PRURL), are URLs that have no protocol specified. For example, <code>//example.com</code> will use the protocol of the current page, typically HTTP or HTTPS.<ref>{{cite book |author-last=Glaser |author-first=J. D. |url={{GBurl|id=6u2sBAAAQBAJ|p=193}} |title=Secure Development for Mobile Apps: How to Design and Code Secure Mobile Applications with PHP and JavaScript |date=March 10, 2014 |publisher=CRC Press |isbn=978-1-48220903-7 |edition=1st |page=193 |language=en-US |access-date=12 October 2015}}</ref><ref>{{cite book |author-last=Schafer |author-first=Steven M. |url={{GBurl|id=DW0uyBZzEDwC|pg=PT124}} |title=HTML, XHTML, and CSS Bible |date=2011 |publisher=John Wiley & Sons|isbn=978-1-11808130-3 |edition=1st |page=124 |language=en-US |access-date=12 October 2015}}</ref>

==See also==  {{div col|colwidth=20em}} * Hyperlink * PURL – Persistent URL * CURIE (Compact URI) * URI fragment * Internet resource locator (IRL) * Internationalized Resource Identifier (IRI) * Clean URL * Typosquatting * Uniform Resource Identifier * URI normalization * Use of slashes in networking {{div col end}}

==Notes== {{notelist|30em}}

==Citations== {{reflist|30em}}

==References== {{refbegin|30em}} * {{cite web |url=http://news.bbc.co.uk/1/hi/technology/8306631.stm |title=Berners-Lee "sorry" for slashes |publisher=BBC News |date=14 October 2009 |access-date=14 February 2010 |ref={{SfnRef|BBC News|2009}} |archive-date=2020-06-05 |archive-url=https://web.archive.org/web/20200605102245/http://news.bbc.co.uk/2/hi/technology/8306631.stm |url-status=live }} * {{cite web |url=http://www.w3.org/Conferences/IETF92/WWX_BOF_mins.html |title=Living Documents BoF Minutes |publisher=World Wide Web Consortium |date=18 March 1992 |access-date=26 December 2011 |ref={{SfnRef|IETF|1992}} |archive-date=2012-11-22 |archive-url=https://web.archive.org/web/20121122075812/http://www.w3.org/Conferences/IETF92/WWX_BOF_mins.html |url-status=live }} * {{cite web |url=http://www.w3.org/Addressing/URL/url-spec.txt |title=Uniform Resource Locators (URL): A Syntax for the Expression of Access Information of Objects on the Network |first=Tim |last=Berners-Lee |author-link=Tim Berners-Lee |date=21 March 1994 |publisher=World Wide Web Consortium |access-date=13 September 2015 |ref={{SfnRef|W3C|1994}} |archive-date=2015-09-09 |archive-url=https://web.archive.org/web/20150909152849/http://www.w3.org/Addressing/URL/url-spec.txt |url-status=live }} * {{cite web |url=http://www.w3.org/People/Berners-Lee/FAQ.html#etc |author-first=Tim |author-last=Berners-Lee |author-link=Tim Berners-Lee |work=Frequently asked questions |title=Why the //, #, etc? |orig-year=2000 |date=2015 |publisher=World Wide Web Consortium |access-date=3 February 2010 |archive-date=2020-05-14 |archive-url=https://web.archive.org/web/20200514191316/https://www.w3.org/People/Berners-Lee/FAQ.html#etc |url-status=live }} * {{cite web |url=http://www.w3.org/html/wg/href/draft#url |title=Web addresses in HTML 5 |editor-first1=Daniel "Dan" |editor-last1=Connolly |editor-link1=Daniel Connolly (computer scientist) |editor-first2=C. Michael |editor-last2=Sperberg-McQueen |editor-link2=C. Michael Sperberg-McQueen |date=21 May 2009 |publisher=World Wide Web Consortium |access-date=13 September 2015 |ref={{SfnRef|W3C|2009}} |archive-date=2015-07-10 |archive-url=https://web.archive.org/web/20150710151425/http://www.w3.org/html/wg/href/draft#url |url-status=live }} * {{cite web |url=http://www.atm.tut.fi/list-archive/ietf-announce/msg13572.html |archive-url=https://web.archive.org/web/20041208124351/http://www.atm.tut.fi/list-archive/ietf-announce/msg13572.html |archive-date=8 December 2004 |title=Completion of IANA Selection of IDNA Prefix |author=IANA |work=IETF-Announce mailing list |date=14 February 2003 |access-date=3 September 2015 |author-link=Internet Assigned Numbers Authority }} * {{cite web |title=An Introduction to Multilingual Web Addresses |date=9 May 2008 |url=http://www.w3.org/International/articles/idn-and-iri/ |access-date=11 January 2015 |ref={{SfnRef|W3C|2008}} |archive-date=2015-01-05 |archive-url=https://web.archive.org/web/20150105041451/http://www.w3.org/International/articles/idn-and-iri/ |url-status=live }} * {{cite web |title=What is Happening with "International URLs" |author-first=A. |author-last=Phillip |url=https://www.w3.org/International/wiki/IRIStatus |publisher=World Wide Web Consortium |date=2014 |access-date=11 January 2015 |ref={{SfnRef|W3C|2014}} |archive-date=2015-02-17 |archive-url=https://web.archive.org/web/20150217192459/https://www.w3.org/International/wiki/IRIStatus |url-status=live }} * {{cite web |last1=Lawrence |first1=Eric |date=2014-03-06 |title=Browser Arcana: IP Literals in URLs |url=https://docs.microsoft.com/en-us/archive/blogs/ieinternals/browser-arcana-ip-literals-in-urls |website=Microsoft Learn |access-date=22 June 2020 |url-status=live |archive-url=https://web.archive.org/web/20200622181648/https://docs.microsoft.com/en-us/archive/blogs/ieinternals/browser-arcana-ip-literals-in-urls |archive-date=22 June 2020 }} {{refend}}

==External links== * [https://url.spec.whatwg.org/ URL specification] at WHATWG * [https://slevithan.github.io/parseuri/demo/ URL splitter] that splits any URI into its parts

Category:URL Category:Identifiers Category:Internet properties established in 1994