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SerpGem
Technical SEO

Sitemap XML Validator

Paste a sitemap XML and verify it against the sitemaps.org 0.9 schema — URL validity, namespace, duplicates, changefreq, priority, and the 50K-URL limit all in one pass.

How to use this tool3 quick steps
  1. Find your sitemap

    Most live at /sitemap.xml — visit https://yoursite.com/sitemap.xml in a browser.
  2. Copy the full XML

    Right-click → View Source (or Ctrl+A → Ctrl+C in the browser). Paste everything below.
  3. Review issues

    We check XML well-formedness, urlset namespace, URL formatting, lastmod date format, priority/changefreq values, and 50,000-URL/50MB limits.
InputSitemap XML
OutputValidation report

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Sitemap Validation Guide

Catch sitemap errors before Google does

Google silently drops invalid sitemap entries — which means you can submit a sitemap, get a 'successful' response in Search Console, and still have half your URLs ignored. This tool validates the same way Google does: URL-by-URL, with clear error messages for each.

The 50,000 URL limit

Sitemaps are capped at 50K URLs and 50MB uncompressed. Above that, you need a sitemap index linking to multiple child sitemaps. Every large site hits this — plan for it early.

URL validity

Every <loc> must be a fully-qualified absolute URL under 2,048 characters. Relative URLs, javascript: URLs, and anything over 2K chars get silently dropped.

Namespace requirement

Root element must include xmlns="http://www.sitemaps.org/schemas/sitemap/0.9". Missing the namespace makes the whole sitemap invalid — a common CMS export bug.

changefreq values

Valid values: always, hourly, daily, weekly, monthly, yearly, never. Google ignores changefreq anyway but other crawlers honor it. Invalid values cause the entry to be skipped.

priority is 0.0 to 1.0

Must be a decimal between 0.0 and 1.0. Google ignores priority too, but malformed values still fail validation. Default is 0.5 if omitted.

lastmod in ISO 8601

YYYY-MM-DD or full ISO 8601 timestamp. Other formats (e.g., '01/15/2026' or '15 Jan 2026') cause the entry to be rejected. Good CMSes generate this correctly; custom sitemaps often don't.

Pro Tips

Sitemap index for scale

Once you approach 50K URLs, create a sitemap index that links to multiple child sitemaps. Each child can have its own 50K URLs, so a sitemap index with 50K children scales to 2.5B URLs.

Gzip is fine

Google accepts .xml.gz files transparently. Gzipping cuts bandwidth 80%+ and doesn't require any sitemap-level changes.

Only index canonical URLs

Never include URLs you canonicalize elsewhere or that have a noindex tag. Google crawls them, wastes budget, and reports them as errors. Only canonical URLs belong here.

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Frequently Asked Questions

What's the difference from Google's Search Console sitemap report?
Search Console validates AFTER Google fetches your sitemap — minutes to hours after a change. This tool validates the XML itself, synchronously, with no network round-trip. Catch errors during staging before pushing live.
Does this check URL accessibility?
No — we validate the XML structure only, not whether URLs return 200 OK. For URL status, use a crawler like Screaming Frog or our Redirect Chain Visualizer.
Do I need a sitemap if I have a small site?
Under 50 pages with good internal linking, Google finds everything without a sitemap. Over 50 pages, a sitemap accelerates indexing and catches orphaned pages. Always recommended for commerce, media, and blog sites.
How often should lastmod be accurate?
Only update lastmod when the content genuinely changed. Bumping it on every build ('all pages modified today') trains Google to ignore it. Accurate lastmod means Google prioritizes re-crawling pages that actually changed.