Sitemap missing or invalid

What it detects

sitemap.xml is missing, unreachable, or fails to parse as a valid urlset/sitemapindex document.

Why it matters

A sitemap is the standard way to hand a crawler a complete, authoritative list of a site's pages; without one, an agent must discover pages purely by following links and may miss large parts of the site.

How to fix

- Check for `sitemap.xml` at the domain root and standard alternate paths, and check whether `robots.txt` has a `Sitemap:` directive pointing to it. - Generate a valid `sitemap.xml` (`urlset` or `sitemapindex` per the sitemaps.org schema) listing your crawlable pages, and reference it from `robots.txt` with `Sitemap: https://example.com/sitemap.xml`. - If a sitemap already exists but fails to parse, validate it against the sitemap XSD and fix malformed entries (unescaped `&`, missing `<loc>`, wrong namespace). - Verify: `curl` the sitemap URL, parse it with an XML parser, and confirm it's a well-formed `urlset`/`sitemapindex` reachable from the `robots.txt` directive.

References

• RFC 9309 — Robots Exclusion Protocol
• Sitemaps protocol