Free tool
XML sitemap validator
Quick answer
Paste a sitemap or enter its URL and the validator checks it against the sitemaps.org protocol: a urlset or sitemapindex root, a loc in every entry, absolute URLs on one host, no more than 50,000 URLs, lastmod in W3C date format, and changefreq and priority values the protocol allows. Each problem is listed with what to change.
Errors and warnings
Errors break the file for crawlers: no urlset or sitemapindex root, an entry without a loc, a relative URL, more than 50,000 entries. Warnings are worth fixing but do not break it: a lastmod in the wrong format, a changefreq or priority outside the allowed values, URLs on a different host, duplicates.
Frequently asked questions
What are the limits of a sitemap?
50,000 URLs and 50 MB uncompressed per file. A bigger site splits its URLs across several sitemaps and lists them in a sitemap index.
Does Google use changefreq and priority?
Google has said it ignores changefreq and priority, and uses lastmod when it is consistently accurate. They are still valid in the protocol, so other crawlers may read them.
What date format does lastmod need?
W3C Datetime: a date such as 2026-10-31, or a full timestamp such as 2026-10-31T09:30:00+00:00.