Sitemaps are particularly beneficial on websites where:

The webmaster can generate a Sitemap containing all accessible URLs on the site and submit it to search engines. Since Google, Bing, Yahoo, and Ask use the same protocol now, having a Sitemap would let the biggest search engines have the updated pages information.

Sitemaps supplement and do not replace the existing crawl-based mechanisms that search engines already use to discover URLs. Using this protocol does not guarantee that web pages will be included in search indexes, nor does it influence the way that pages are ranked in search results.[citation needed]

Google first introduced Sitemaps 0.84 in June 2005 so web developers could publish lists of links from across their sites. Google, MSN and Yahoo announced joint support for the Sitemaps protocol in November 2006. The schema version was changed to "Sitemap 0.90", but no other changes were made.

In April 2007, Ask.com and IBM announced support for Sitemaps. Also, Google, Yahoo, MS announced auto-discovery for sitemaps through robots.txt. In May 2007, the state governments of Arizona, California, Utah and Virginia announced they would use Sitemaps on their web sites.

The Sitemaps protocol is based on ideas from "Crawler-friendly Web Servers".

The Sitemap Protocol format consists of XML tags. The file itself must be UTF-8 encoded. Sitemaps can also be just a plain text list of URLs. They can also be compressed in .gz format.

A sample Sitemap that contains just one URL and uses all optional tags is shown below.

The definitions for the elements are shown below :

'Always' is used to denote documents that change each time that they are accessed. 'Never' is used to denote archived URLs (i.e. files that will not be changed again).