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FixAEO
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Free Sitemap Validator

Paste your sitemap.xml. We check URL count, lastmod coverage, staleness, duplicates, HTTPS, and 5 other AEO signals.

Paste sitemap.xml

XML content

Fetch yoursite.com/sitemap.xml in your browser, View Source, paste here.

Paste your sitemap.xml content and we'll validate structure, count URLs, check lastmod coverage + freshness, and flag duplicates.

What we check

Eight categories of sitemap issue, with concrete fixes.

Structure + size

Validates root element, XML declaration, encoding. Counts URLs against Google's 50,000 limit. Detects sitemap index vs URL sitemap.

lastmod + freshness

Reports % of URLs with lastmod set, identifies URLs not updated in 12+ months, flags sitemaps that are mostly stale.

Duplicates + HTTPS

Catches duplicate <loc> entries (wasted bytes), non-HTTPS URLs (trust downgrade), and other AEO red flags.

Frequently asked questions

What's the URL limit per sitemap?
Google's hard limit: 50,000 URLs OR 50 MB uncompressed per sitemap.xml. Past that, split into multiple sitemaps and reference them from a sitemap index. We warn at 30,000 URLs so you have runway.
Why does lastmod matter?
Crawlers (Google + AI bots) re-fetch URLs based on lastmod. If you don't populate it, they fall back to heuristics — meaning your updated content is rediscovered slower. Aim for lastmod on every URL.
What about stale URLs?
URLs not updated in 12+ months are flagged. Some old URLs are fine (your About page doesn't need to be 'fresh'); a sitemap that's 80% stale signals neglected content to crawlers and AI assistants.
Sitemap index vs URL sitemap?
A URL sitemap (<urlset>) contains <url> entries — your actual page list. A sitemap index (<sitemapindex>) contains <sitemap> entries pointing to other sitemap files — used when you need multiple sitemaps. We auto-detect which you pasted and check accordingly.
Why are non-HTTPS URLs flagged?
http:// triggers mixed-content warnings in Google Search Console, and AI crawlers may downgrade trust signals for non-HTTPS pages. There's no reason to have http URLs in a 2026 sitemap — fix them and 301 redirect.

Full site audit?

The FixAEO scan validates sitemap.xml + 9 other AEO signals across your whole site.

Run a free AEO audit