XML sitemap
Also called sitemap.xml, Sitemap protocol.
What XML sitemap means
An XML sitemap is a file that lists the URLs on a site so search engines can learn about pages available for crawling. The Sitemap protocol at sitemaps.org is explicit that using it "does not guarantee that web pages are included in search engines, but provides hints for web crawlers to do a better job of crawling your site."
More precisely
Protocol version 0.9 requires three tags: `urlset` wrapping the file, `url` for each entry, and `loc` for the address, which must begin with the protocol. Optional tags include lastmod, changefreq and priority, and the protocol notes that changefreq "is considered a hint and not a command." A single file is capped at 50,000 URLs and 50MB, with sitemap index files used beyond that. It is a multi-engine agreement published under a shared licence rather than an IETF standard.
Why it matters
A sitemap mainly helps discovery of pages that internal links reach weakly or not at all. It is a way of telling crawlers a URL exists, and nothing in the protocol promises anything about what happens next.
Example
The file is usually declared with a `Sitemap:` line in robots.txt as well as submitted directly in a search console.
Where this came from
Definitions here follow the specification or documentation that defines the term, not a paraphrase of another glossary.
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Sitemaps XML format — sitemaps.org
Protocol version 0.9, the three required tags, the 50,000 URL and 50MB limits, and the statement that changefreq is a hint and not a command.
Primary source · read 2026-09-03
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sitemaps.org home — sitemaps.org
Sitemaps inform search engines about pages available for crawling, and using the protocol does not guarantee inclusion.
Primary source · read 2026-09-03