Sitemap errors: XML, server responses and page URLs

Check the response before the XML

A sitemap URL can return a login page, a CDN challenge or an HTML error with status 200. Inspect the final response and actual body. In the report, distinguish an HTTP failure, incomplete download and XML parse failure. Fix the layer producing the unexpected content first.

Start with a small valid document

This XML example contains two absolute URLs. The ampersand in the query is escaped as & in XML and becomes & in the parsed URL. Replace both URLs with intended public canonical pages; the search URL only demonstrates escaping. Do not copy an example URL list as your site inventory.

<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
  <url><loc>https://example.com/</loc></url>
  <url><loc>https://example.com/search?a=1&amp;b=2</loc></url>
</urlset>

Understand what this checker inspects

check.uk.app reads one same-origin sitemap declared in robots.txt, or tries /sitemap.xml. It checks that single XML document and shows an entry count and sample. It does not fetch child maps or visit the listed pages. A parsed sitemap index therefore does not validate its children.

The fetch and parser have safety limits. A document exceeding the service limit is not automatically invalid under the sitemap protocol. A syntactically parsed file is not full schema, ownership or search-engine validation.

Review URLs and file limits

Keep the list consistent with your canonical public pages. Check sample URLs for redirects, errors, noindex and access restrictions separately. Use accurate modification dates when available, not a timestamp refreshed on every build.

A standard sitemap has a maximum of 50,000 URLs and 50 MB uncompressed. Larger collections need multiple maps and an index. For cross-site submission or specialized extensions, follow the relevant search engine’s rules rather than assuming a same-origin checker covers them.

Publish, compare and monitor

Back up the current generator and output. Validate the new XML, check the public response, then inspect the sitemap in Search Console for your property. Submission helps discovery but does not guarantee indexing. If generation breaks, restore the previous valid output while fixing the source.

Our example is tested with the same parser used by the service: two entries are read, the escaped URL is decoded and deliberately malformed XML is rejected. No listed page is crawled by this fixture.