Keep XML sitemaps valid

An invalid or malformed sitemap is silently ignored by search engines, leaving newly published or orphaned pages undiscovered by crawlers.

Quick Reference

• The root element must be <urlset> with the correct xmlns namespace
• Each <url> must contain exactly one <loc> element with a fully qualified, percent-encoded URL
• Maximum 50,000 URLs and 50 MB per sitemap file; use a sitemap index for larger sites
• Encode XML special characters: & → &, < → <, > → >, " → ", ' → '

Check

Fetch the sitemap and validate it against the sitemaps.org schema. Check that the xmlns attribute is http://www.sitemaps.org/schemas/sitemap/0.9, all <loc> values are absolute URLs, no file exceeds 50,000 URLs or 50 MB, and special characters are properly XML-encoded.

Fix

Re-generate the sitemap using a validated sitemap library. Encode all special characters in URLs (& → &). Split oversized sitemaps into multiple files and reference them from a sitemap index. Resubmit to Google Search Console.

Explain

Explain the sitemaps.org XML schema requirements, what causes validation errors in Google Search Console, and how encoding errors in <loc> URLs prevent crawlers from fetching those pages.

Code Review

Review metadata generation, rendered HTML, structured data, and response headers related to Keep XML sitemaps valid. Flag exact routes or templates where search-facing output violates the rule, and describe how to verify the final page output.

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For full implementation details, code examples, and framework-specific guidance, see references/rule.md.

Rule page: https://frontendchecklist.io/en/rules/seo/sitemap-valid