Agent-friendly documentation: a Markdown index for AI agents is at /llms.txt. Every page is also available as clean Markdown by appending .md to its URL (e.g. /pricing.md), or by requesting it with an Accept: text/markdown header.

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Sitemap Validator

Validate an XML sitemap's structure, URLs, and freshness fields.

How it works

Enter your sitemap URL — or any page on the site and the validator finds /sitemap.xml itself. It checks the XML structure against the sitemaps.org schema, follows a sitemap index one level deep, and counts every URL entry.

Every <lastmod> value is validated as a real W3C datetime, and up to ten listed URLs are sample-checked live so a sitemap full of 404s gets caught before crawlers lose trust in it.

The full result — structure, counts, date problems, and dead sampled URLs — downloads as CSV or JSON, free and instant.

Frequently asked questions

Does it handle sitemap index files?

Yes. A <sitemapindex> is followed one level deep: the child sitemaps are fetched and their URL entries validated together, with analysis capped at the first 2,000 entries so huge sites still finish fast.

Why do lastmod dates matter?

Search engines use <lastmod> to prioritize recrawling — but only when the dates are trustworthy. Invalid formats get ignored, and dates that never change teach crawlers to ignore the whole field.

What does the sample check actually do?

Up to ten URLs spread across the sitemap are requested live. Any that fail to return a 2xx response are listed with their status, because sitemaps that advertise dead pages erode crawler confidence in every other entry.

Sitemap clean. Now earn the crawl budget.

BuildSEO AI builds the verified backlinks that make crawlers care about your sitemap.

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