XML Sitemap Checker: Validate a Sitemap or Index

Validate a sitemap or sitemap index and count its URLs.

Use via API

Fetch an XML sitemap or sitemap index (up to 5 MB each, 50 child sitemaps), count URLs and report invalid XML, lastmod, http, off-host and duplicate URLs. Send JSON, get JSON back; this one reaches the network from PithLab’s server.

POST https://pithlab.com/api/v1/tools/sitemap-checker

curl https://pithlab.com/api/v1/tools/sitemap-checker \
  -H "Authorization: Bearer $PITHLAB_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url":"https://www.sitemaps.org/sitemap.xml"}'

Fields and response OpenAPI document Get an API key

About the Sitemap Checker

Fetch an XML sitemap or sitemap index, count its URLs and check the XML, lastmod dates, http and off-site URLs, duplicates and size limits, with a sample of entries.

How to use the Sitemap Checker

Enter a sitemap URL, such as https://example.com/sitemap.xml. Enter just a site and /sitemap.xml is tried.
Press Check. PithLab's server fetches it (up to 5 MB, gzip included). For a sitemap index, up to 50 of the sitemaps it lists are fetched too.
Read the URL count, each child sitemap's result, the problems grouped with examples, and a sample of the first entries.

Examples

A bad lastmod date

Input

<url><loc>https://example.com/</loc><lastmod>20/10/2026</lastmod></url>

Output

lastmod isn't in W3C Datetime format (such as 2026-10-20 or 2026-10-20T09:30:00+00:00).

Frequently asked questions

What are a sitemap's limits?

Each sitemap file can hold at most 50,000 URLs and 50 MB uncompressed. Larger sites split their URLs across several sitemaps and list them in a sitemap index. This checker reads up to 5 MB per file.

What format should lastmod use?

W3C Datetime: a date such as 2026-10-20, or a date and time with a time zone, such as 2026-10-20T09:30:00+00:00. Google uses lastmod only when it's consistently accurate, so set it to when the content really changed.

Why are URLs on another host flagged?

A sitemap should only list URLs on its own host. Search engines ignore other hosts' URLs unless you've proven you own both sites, for example in Search Console.