Sitemap Validator

Sitemap Validator

Validate XML, TXT, RSS/Atom, and gzip sitemaps right from your browser — no accounts, no uploads to third-party servers, no waiting. Just open a sitemap, click the icon, and get a complete audit in seconds.

WHAT IT CHECKS
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Sitemap Validator goes beyond basic XML linting. It audits the things that actually affect how search engines crawl your site:

✅ Structural correctness — XML syntax, root tags, namespace, URL count limits, missing <loc> tags, URL schemes, URL length, and UTF-8 encoding are all verified against the official sitemaps.org specification.

✅ Lastmod quality — Detects invalid date formats, future dates, and suspiciously concentrated lastmod values that signal to Google that your timestamps can't be trusted.

✅ Domain authority — Flags URLs that belong to domains outside the sitemap's authority, including cross-domain mismatches and subdomain URLs that haven't been confirmed via robots.txt.

✅ robots.txt consistency — Cross-checks every URL against the site's robots.txt and warns when entries match a Disallow rule. Blocked URLs cannot be indexed, so they shouldn't be in the sitemap. Counts, percentages, and examples are surfaced inline.

✅ Duplicate URL detection — Detects URLs that appear more than once in a single sitemap, and (when validating a sitemap index) URLs that appear across multiple child sitemaps. Duplicates waste crawl budget and provide no indexing benefit.

✅ Orphan check — Tells you whether the page you're currently viewing is listed in the validated sitemap. Useful for catching important pages that have been accidentally left out.

✅ Harmless clutter — Reminds you when <priority> or <changefreq> tags are present. Google has stated publicly that it ignores both. Knowing this keeps your sitemap clean without wasting time on non-issues.

✅ Extension sitemaps — Detects image, video, news, and mobile sitemap namespaces and validates their required fields and value formats. Extension types are shown as badge icons (🖼️ 🎬 📰 📱) in the popup header and in the discovered sitemap list. The deprecated mobile extension (`xmlns:mobile`) is flagged with a warning.

✅ hreflang — For international sites, a dedicated tab checks namespace declarations, self-referencing links, duplicate language codes, BCP 47 format, x-default consistency, reciprocal link integrity, and unofficial region codes (like "UK" instead of "GB"). A language-coverage matrix lets you spot gaps at a glance.

✅ Live URL inspection — After validation, the extension automatically fetches a sample of 20 URLs and checks each one for HTTP status, redirects, canonical URL matches (✓/✗), lastmod drift (+N days / −N days), and noindex signals. Hover any cell for details — redirect destinations, side-by-side page/canonical URL comparison, and more. You can run additional checks in batches, filter results by issue type, or search by URL substring. URLs marked noindex are also escalated to a warning in the summary, since Google recommends excluding them from sitemaps. If you close the popup mid-check, the remaining URLs continue processing in the background and the results are restored when you reopen it. Export everything to CSV when you're done.

📊 HEALTH SCORE
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Every audit produces a 0–100% health score that weighs errors, warnings, and live URL results together. The score is shown as an SVG ring at the top of the summary panel, accompanied by a contextual message ("Issues require your attention", "Some items could be improved", or "No issues detected") and chips that break down the counts for errors, warnings, passes, and URL sample results. Green means your sitemap is in good shape. Yellow means there are issues worth addressing. Red means something needs fixing before you submit to Search Console.

Score calculation excludes <priority> and <changefreq> — penalizing their presence would be misleading, since removing them doesn't actually improve crawlability.

🔍 SITEMAP DISCOVERY
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You don't always need to know a sitemap's URL in advance. Sitemap Validator reads the current page's robots.txt and lists every sitemap it finds. A badge icon (✓) appears on tabs where a sitemap was detected. Validate any of them with one click — or run a bulk check across all discovered sitemaps at once.

Validation results stay available as you browse within the same site. They're only cleared when you navigate to a different domain or close the tab.

📂 LOCAL FILE VALIDATION
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Working on a sitemap before it goes live? Use the 📂 button to load a file directly from your computer. The extension treats it as if it were hosted on the current tab's domain, so domain authority checks still make sense. No file ever leaves your machine.

ℹ️ TRANSPARENCY PER CHECK
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Every check result has an ℹ icon. Click it to see the exact passage from the sitemaps.org spec or Google Search Central documentation that the check is based on. When a colleague asks why something is flagged, you'll have a source to point to.

📄 XML VIEWER
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The built-in XML viewer lets you inspect the raw sitemap source inline, switch to a formatted (indented) view with one click, and copy the contents to the clipboard.

HOW TO USE
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1. Open any sitemap URL (e.g. https://example.com/sitemap.xml), or navigate to any page on the site you want to audit.
2. Click the Sitemap Validator icon in the Chrome toolbar.
3. The sitemap URL fills in automatically. Hit Validate — or load a local file with 📂.
4. Review the health score and work through errors and warnings from top to bottom.
5. Check the URL Sample tab to see how your URLs behave in practice.
6. If your sitemap uses hreflang, open the hreflang tab to verify language coverage.
7. Any sitemaps found in robots.txt appear at the bottom — validate them individually or in bulk.

🔒 PRIVACY & PERMISSIONS
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Everything runs locally. Your sitemap content and audit results never leave your browser — they're held in Chrome's session storage and cleared automatically when you close the tab or the browser.

The extension requests:
• activeTab and tabs — to read the current tab's URL and detect sitemaps automatically
• storage — to keep your results available while you browse the same site
• Access to all URLs — to fetch sitemaps and check individual URLs on your behalf, directly from the extension without any proxy

LANGUAGE
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Available in English and Japanese. The interface follows your browser's UI language automatically.