SitemapForge

Sitemap validator

Check an XML sitemap the way a search engine reads it: protocol errors, limits, lastmod trust, hosts, and a live spot check of the URLs inside.

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Errors, warnings and info, explained

Errors break the rules in the sitemaps.org protocol: XML that doesn't parse, a missing namespace, relative URLs, invalid dates, more than 50,000 URLs or 50 MB in one file. Google Search Console reports these as "Sitemap could not be read" or per-entry errors.

Warnings are legal but costly. Duplicate URLs, mixed www and bare hosts, tracking parameters and a lastmod that is identical everywhere don't stop Google reading the file, but they dilute what the sitemap tells it.

Info notes flag things that look alarming but aren't, like priority and changefreq, which are valid XML that Google has said it ignores.

Why a valid sitemap can still be a bad one

The XML only proves the list is readable. Search Console's "Submitted URL has crawl issue", "Submitted URL marked noindex" and "Page with redirect" reports come from what's behind each URL. That is why the validator can fetch a spread-out sample of 25 URLs and test each one for a 200 status, indexability and a self-referencing canonical.

Questions people ask

What does the sitemap validator check?
Well-formed XML, the sitemaps.org namespace, the root element (urlset or sitemapindex), absolute URLs, the 50,000-URL and 50 MB limits, W3C date format in lastmod, valid changefreq and priority values, duplicate URLs, mixed hosts and www/non-www, #fragments and tracking parameters, missing extension namespaces for image and hreflang tags, future or uniform lastmod dates, and HTTP details such as redirects and content type.
Is a sitemap with warnings still valid?
Yes. Errors break the protocol and can make Google reject the file or skip entries. Warnings are quality problems (duplicates, mixed hosts, suspicious lastmod dates) that waste crawling or make your signals less trustworthy. Info notes are neutral.
Can I check a sitemap index?
Yes. The validator recognises a sitemapindex, lists every child sitemap and lets you validate each one with one click.
Why does it say my lastmod dates look fake?
When 90% or more of URLs share one lastmod date, the site is usually stamping the build or deploy date on every page. Google's sitemap guide says lastmod is used only when it is consistently and verifiably accurate, so a uniform date can make Google ignore the field for your site.
What is the live spot check?
A sitemap can be perfectly formed and still list broken pages. The spot check fetches up to 25 URLs spread across the file and reports redirects, errors, noindex pages and pages whose canonical points elsewhere. It checks a sample, not the whole file.
Can it read .xml.gz files?
Yes, both by URL and by upload. Uploads are decompressed and parsed in your browser, so there is no size limit.