Editing HTTP 404 (section)

==Custom error pages==
[[File:Wikimedia error 404.png|thumb|The Wikimedia 404 message]]

[[Web server]]s can typically be configured to display a customised 404 error page, including a more natural description, the parent site's branding, and sometimes a site map, a search form or 404-page widget. The protocol level phrase, which is hidden from the user, is rarely customized. [[Internet Explorer]], however, will not display custom pages unless they are larger than 512 bytes, opting instead to display a "friendly" error page.<ref>{{cite web|url=http://blogs.msdn.com/b/ieinternals/archive/2010/08/19/http-error-pages-in-internet-explorer.aspx|title=Friendly HTTP Error Pages|date=18 August 2010|publisher=msdn.com|access-date=14 June 2012|archive-url=https://web.archive.org/web/20101202044514/http://blogs.msdn.com/b/ieinternals/archive/2010/08/19/http-error-pages-in-internet-explorer.aspx|archive-date=2 December 2010|url-status=dead}}</ref> [[Google Chrome]] included similar functionality, where the 404 is replaced with alternative suggestions generated by Google algorithms, if the page is under 512 bytes in size.<ref>{{Cite web|title=Issue 1695: Chrome needs option to turn off "Friendly 404" displays|url=https://bugs.chromium.org/p/chromium/issues/detail?id=1695|access-date=2021-12-25|website=bugs.chromium.org}}</ref> Another problem is that if the page does not provide a [[favicon]], and a separate custom 404-page exists, extra traffic and longer loading times will be generated on every page view.<ref>{{cite web|url=http://www.thesitewizard.com/archive/favicon.shtml|title=What is Favicon.ico and How to Create a Favicon Icon for Your Website|last=Heng|first=Christopher|date=7 September 2008|website=The Site Wizard|access-date=23 February 2011}}</ref><ref>{{cite web|url=http://internetfolks.com/dastardly-favicon-ico-found-error/|title=The Dastardly "favicon.ico not found" Error|date=3 August 1999|work=Internet Folks}}</ref>

Many organizations use 404 error pages as an opportunity to inject humor into what may otherwise be a serious website. For example, Metro UK shows a polar bear on a skateboard, and the web development agency Left Logic has a simple drawing program.<ref>{{cite news|url=http://metro.co.uk/2013/04/16/from-skateboarding-bears-to-missing-children-the-power-of-the-404-not-found-error-page-3591031/|title=From skateboarding bears to missing children: The power of the 404 Not Found error page|date=6 June 2011|access-date=16 April 2013|publisher=Metro}}</ref> During the [[2015 United Kingdom general election|2015 UK general election]] campaign the main political parties all used their 404 pages to either take aim at political opponents or show relevant policies to potential supporters.<ref>{{cite web|url=http://www.bbc.co.uk/newsbeat/article/32480181/the-political-page-404-war|title=The political Page 404 war|date=27 April 2015|website=BBC Newsbeat|access-date=18 May 2018}}</ref> In Europe, the [[NotFound project]], created by multiple European organizations including [[Missing Children Europe]] and [[Child Focus]], encourages site operators to add a [[Snippet (programming)|snippet of code]] to serve customized 404 error pages<ref>{{cite web|title=Notfound.org|url=http://notfound.org/notfound|url-status=dead|archive-url=https://web.archive.org/web/20140902081543/http://notfound.org/notfound|archive-date=2 September 2014|website=notfound}}</ref> which provide data about [[missing children]].<ref>{{cite news|url=https://www.bbc.com/news/technology-19741350|title=Missing children messages go on 404 error pages|date=27 September 2012|work=[[BBC News]]|access-date=20 September 2014}}</ref>

While many websites send additional information in a 404 error message—such as a link to the [[homepage]] of a website or a search box—some also endeavor to find the correct web page the user wanted. Extensions are available for some [[content management system]]s (CMSs) to do this.<ref>{{cite web|url=http://googlewebmastercentral.blogspot.com/2008/08/make-your-404-pages-more-useful.html|title=Make your 404 pages more useful|last=Swenson|first=Sahala|date=19 August 2008|work=Official Google Webmaster Central Blog|publisher=Google, Inc|access-date=28 August 2009}}</ref>