← Sitemap lastmod Freshness Check
XML-Sitemaps.com's Sitemap Validator is a well-known free tool in the SEO
community for checking a sitemap.xml file's own structure: is it well-formed XML,
does it declare the right namespace, are the required tags present, and does it stay within the
sitemap protocol's size and URL-count limits. For catching a hand-edit or a generator bug that
produced broken XML, it is a solid, established first check.
Sitemap lastmod Freshness Check assumes your XML is already structurally fine and checks a completely different property: whether the <lastmod> values themselves are telling the truth. A sitemap can be perfectly valid XML — every tag closed, every namespace correct — and still have every single <lastmod> set to today's date regardless of whether the page changed, or set to a date in 2099, or list the same URL twice with two different dates. None of that is an XML-schema violation, so a schema validator has no reason to flag it — and this tool exists specifically for that gap.
| Question | Where to answer it |
|---|---|
| I just generated or hand-edited a sitemap.xml and want to know if the XML itself is valid. | XML-Sitemaps.com's Sitemap Validator — structural/schema validation is its job. |
| My sitemap validates fine, but I suspect the <lastmod> dates are wrong, uniform, or fake. | Sitemap lastmod Freshness Check — this is exactly the property a schema validator does not look at. |
| I want to know if a URL's <lastmod> claim is actually confirmed by the live page. | Sitemap lastmod Freshness Check's CLI — node check.mjs <sitemap-url> fetches each URL's real HTTP Last-Modified header and cross-checks it. A schema validator has no live-page step at all. |
| I want this checked automatically on every build, before it ships. | Sitemap lastmod Freshness Check's CLI exits non-zero on a finding, wireable into any CI as an ordinary step, with no account or hosted service in the loop. |
Neither tool replaces the other. Run a schema validator first if you have any doubt the XML itself is well-formed — a broken sitemap will confuse both tools and every crawler equally. Once the structure is confirmed sound, this tool answers the question a schema check was never built to ask: do the dates inside it actually mean anything?
Different jobs, and many sites need both. XML-Sitemaps.com's Sitemap Validator checks that your sitemap.xml is well-formed and structurally correct per the sitemap protocol's XML schema — the right first check for a newly generated or hand-edited sitemap. Sitemap lastmod Freshness Check assumes the XML is structurally fine and checks a different property entirely: whether the <lastmod> dates inside it are individually valid, internally consistent, plausible, and (via the CLI) actually confirmed by each page's own HTTP Last-Modified response header.
Based on its own public description, its Sitemap Validator checks XML syntax and schema conformance — structure, not the semantic plausibility of individual field values across the file, and it does not fetch each listed URL's own page to cross-check the date against reality. It is a schema validator, not a lastmod-truthfulness checker, which is a different and narrower job than this tool does.
Yes, based on its own public listing — the Sitemap Validator needs no account for a basic check. Sitemap lastmod Freshness Check is also free, with no account, and the two are not competing on price — the difference is what each one actually checks.
No. This site is not affiliated with, endorsed by, or sponsored by XML-Sitemaps.com. XML-Sitemaps.com and its Sitemap Validator are named here only to describe what that tool does and how it differs from this one, based on its own public description.