Create a sitemap index file that lists your child sitemaps.
How to use the Sitemap index generator
- Paste the child sitemap URLs.
- Download the index.
- Submit the index in Search Console.
When you need an index
When you have more than 50,000 URLs or want separate sitemaps per section (products, blog, pages) to track indexing for each.
What the file contains
One sitemap entry per child URL you paste, with that child's address and today's date as lastmod. Only lines starting with http:// or https:// are used. An index can hold up to 50,000 child sitemaps. Save it as sitemap_index.xml (or any name) at the site root, and point the Sitemap: line in robots.txt at the index rather than at each child. If a child hasn't changed in a while, you can edit its lastmod back to the real date before uploading.
Common index mistakes
Listing URLs of normal pages instead of sitemaps. Child sitemaps on another domain without verifying both in Search Console. Children that 404 because their names changed. Mixing http and https addresses. After uploading, run the index through the sitemap validator: it fetches every child and flags any that fail.