What a healthy sitemap looks like
An XML sitemap lists the canonical, indexable URLs you want search engines to find. Each file may hold up to 50,000 URLs and 50 MB uncompressed. Larger sites split URLs across several files and list them in a sitemap index.
Every URL in the sitemap should return HTTP 200 directly, use the same protocol and host as the site, and not carry a noindex tag. Redirects and errors in a sitemap waste crawl budget and make Google trust the file less.
Getting lastmod right
The lastmod element tells Google when a page last changed in a meaningful way. Use the W3C date format, for example 2026-11-07 or 2026-11-07T10:30:00+00:00, and only update it when the content changes. Google ignores lastmod values it finds to be consistently inaccurate.
Make sure crawlers can find it
Add a Sitemap: line with the absolute URL to robots.txt, and submit the sitemap in Google Search Console and Bing Webmaster Tools. This tool checks robots.txt first and falls back to /sitemap.xml.
Frequently asked questions
Do I need a sitemap for a small site?
Small, well-linked sites can be crawled without one, but a sitemap still helps search engines find new pages faster and is cheap to maintain.
Should priority and changefreq be set?
Google ignores the priority and changefreq elements. Accurate lastmod values are more useful.
Why does this tool only test a sample of URLs?
Testing every URL of a large sitemap takes a long time. A spread-out sample of 15 URLs catches systematic problems such as redirects or errors. A full audit checks far more pages.