Paste the contents of several sitemap.xml files at once — separated by a page-break line — and validate each against the Sitemap Protocol in one pass: malformed XML, invalid priority/changefreq/lastmod values, duplicate URLs, and missing required tags.
Paste full sitemap.xml contents. Separate multiple sitemaps with a line containing just -----. Optionally start a sitemap's block with ### name to label it in the results.
Well-formed XML — unclosed tags, mismatched nesting, or unescaped &/</> characters in a URL make the whole file unparseable, which means search engines can't read any of it, not just the broken part. Missing <urlset> or <loc> — these are required by the Sitemap Protocol; a URL entry with no <loc> is meaningless. Relative URLs — the spec requires absolute URLs (https://example.com/page, not /page); a relative path has no defined domain for a crawler to resolve it against. Invalid <priority> — must be a number between 0.0 and 1.0; anything outside that range is a spec violation (though Google has said it mostly ignores this value regardless). Invalid <changefreq> — must be one of always, hourly, daily, weekly, monthly, yearly, or never; anything else isn't a recognized value. Duplicate URLs — the same <loc> listed more than once in one sitemap, usually from a generation bug rather than intentional.
Sites with more than a few thousand pages commonly split their sitemap into several files (one per content type — pages, blog posts, products) or use a sitemap index referencing multiple child sitemaps. A generation bug in a shared template — a script that produces sitemaps for both the blog and the product catalog, say — often shows up identically across every file it touches. Validating them together surfaces that pattern immediately, rather than finding the same bug five separate times across five separate single-file checks.
Not directly in any severe way — Google has stated it largely ignores changefreq and treats priority as a very weak signal at best, relying on its own crawl data instead. They're still worth fixing for spec compliance and because other search engines or tools consuming your sitemap may handle them more strictly, but a wrong value here is a minor issue, not a critical one like a malformed XML file that can't be parsed at all.
It's a spec violation, and behavior on non-conformant sitemaps isn't guaranteed to be consistent across every crawler or every situation. Some crawlers may resolve a relative URL against the sitemap's own location and get it right by luck; the safe fix is always absolute URLs, since that's what the spec actually requires.
It checks the XML structure and tag validity of whatever you paste in, including a sitemap index's <sitemapindex>/<sitemap> structure — but since this tool works from pasted text rather than fetching URLs, it won't automatically follow references to the child sitemaps; paste each one in separately (as its own block) to validate them all.