What are custom 404 pages?
When someone experiences a 404 error, the default behavior of a web server is to display a standard error message page indicating that the requested resource could not be found. However, because 404 errors are relatively common, it often helps to have a nicer page that maintains the look and feel of the web site when 404 errors occur. Such pages are generally referred to as custom 404 pages and are defined by a configuration setting appropriate to the web server software being used. One important thing to consider is that a custom 404 error page must never attempt to rely on a resource on the same web server which does not or may not exist at some point in the future. If a custom 404 error page was to do so, accessing the custom page would itself generate a custom 404 error response and result in an infinite loop.
last updated 2008.01.06