What this check does
It uses a sitemap declared in robots.txt when available, otherwise tests the conventional /sitemap.xml location. It reports the response, basic XML parsing, sitemap index versus URL set, and counted locations.
Free technical SEO tool
XML Sitemap Checker
Check whether a public sitemap can be discovered and read as basic XML.
What this check does not prove
A sitemap can support discovery but does not mean Google indexed the URLs. This focused check does not crawl unlimited nested sitemap indexes.
Want the complete technical picture?
A sitemap is more useful when it agrees with public crawlability, canonical and indexing directives.