Sitemap Validator

The validator runs two passes. First it checks the sitemap itself: valid, well-formed XML; the correct urlset namespace; a <loc> for every entry; absolute HTTPS URLs on the right host; sensible lastmod dates; and no duplicate URLs. If you submit a sitemap index, it recurses into each child sitemap and checks them too.

Then it does what a syntax checker won’t: a live health check of the URLs inside. It requests each one and reports the status, so you can see the dead links (404s) and redirect chains (301s and 302s) that are wasting crawl budget - the gap between a sitemap that looks valid and one that actually is.

• Dead URLs (404s) - remove pages that no longer exist. A sitemap full of 404s tells crawlers the whole file is unreliable.
• Redirecting URLs (301/302) - list the final destination, not a URL that redirects. Sitemaps should point straight at the live page.
• Wrong host or protocol - every URL must be on the same site and use HTTPS. Mixed http/https or bare domains are a common cause of ignored entries.
• Duplicate or non-canonical URLs- list each page once, at its canonical URL, so you’re not sending mixed signals.
• A stale or fake lastmod - use a real last-modified date. If every entry says today, crawlers learn to ignore the field.

Strip away the parts of the spec that don’t matter and the rules are short: a sitemap must be UTF-8 encoded, hold no more than 50,000 URLs, and be under 50MB uncompressed. URLs must be fully-qualified and absolute, and should sit on the same host as the sitemap. Special characters in URLs have to be XML-escaped.<loc> is required; an accurate <lastmod> is used; and priority and changefreq are ignored entirely.

Here’s a minimal, valid sitemap that meets every requirement above:

<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
  <url>
    <loc>https://example.com/</loc>
    <lastmod>2026-07-21</lastmod>
  </url>
  <url>
    <loc>https://example.com/pricing</loc>
    <lastmod>2026-07-18</lastmod>
  </url>
</urlset>

AI crawlers like GPTBot, ClaudeBot and PerplexityBot discover pages much the way search engines do - and a clean sitemap gives them a direct, complete list of your URLs instead of leaving them to find pages through links. If a page isn’t linked from anywhere prominent, your sitemap may be the only way an AI engine finds it at all.

A sitemap works best alongside two other files. Your robots.txt should reference the sitemap and allow the AI crawlers you want; an llms.txt gives AI models a curated summary of your best content. Together they make your site as easy as possible for AI engines to reach, read and cite.