Sitemap Index Generator

A sitemap index is an XML file that lists other sitemap files instead of pages. Large sites use one because a single sitemap can only hold 50,000 URLs or 50 MB. You submit the index to search engines once, and they find every sitemap inside it.

It loads each sitemap, four at a time, and confirms it returns a 200 status and is a valid urlset. It counts the URLs inside and finds the newest lastmod, which can be used as the lastmod for that sitemap in the index. Up to 500 sitemaps are checked per run.

The lastmod of a sitemap entry should be the time that sitemap file last changed. Using the newest lastmod found inside the sitemap is a good approximation. Avoid setting every entry to today unless every sitemap really did change today, because inaccurate dates teach search engines to ignore them.

No. The protocol doesn't allow nested indexes. The checker flags any entry that turns out to be an index, and you should list its child sitemaps directly instead.

By default, a sitemap index should only list sitemaps on the same host as the index. Cross-host listings only work if you've verified ownership of both sites, for example in Google Search Console. The tool warns you when hosts don't match.

Upload it to your site's root, for example https://example.com/sitemap_index.xml. Then add a Sitemap line pointing to it in robots.txt and submit it in Google Search Console and Bing Webmaster Tools.