You created a sitemap index and submitted it, but child sitemaps are not read. Or only some of them are processed. Or Google reports errors. Sitemap index is useful for large sites, but it has specific requirements. This guide explains why your sitemap index is not working and how to fix it.
What a sitemap index does
A sitemap index is an XML file that lists other sitemap files. It is used when a site has more than 50,000 URLs or a sitemap larger than 50 MB.
Structure:
<sitemapindex>
<sitemap><loc>https://example.com/sitemap1.xml</loc></sitemap>
<sitemap><loc>https://example.com/sitemap2.xml</loc></sitemap>
</sitemapindex>
Each child sitemap must be accessible and valid. If any child is invalid, the index may not work correctly.
Reason 1: child sitemap URLs are wrong
The most common issue: child sitemap URLs in the index are wrong. They may point to non-existent files, use relative URLs or have typos.
What to check:
— are child URLs absolute;
— do they return 200;
— are they accessible without authentication;
— are there typos.
Use sitemap checker to verify that all child sitemaps are accessible and valid.
Reason 2: child sitemaps exceed limits
Each child sitemap must not exceed 50,000 URLs or 50 MB. If a child exceeds the limit, it may not be read.
What to check:
— number of URLs in each child;
— file size of each child;
— whether child sitemaps need to be split further.
Reason 3: child sitemaps are not valid XML
If a child sitemap is not valid XML, the index may not process it.
What to check:
— valid XML;
— correct encoding;
— no BOM;
— correct structure.
Reason 4: index is not accessible
If the index itself is not accessible, Google cannot read child sitemaps.
What to check:
— index returns 200;
— index is not blocked by robots.txt;
— index is not behind authentication;
— index is not blocked by firewall.
Reason 5: index not submitted or not verified
If the index is not submitted in Search Console, or the property is not verified, Google may not know about it.
What to check:
— index submitted in Search Console;
— property verified;
— index listed in robots.txt;
— errors in Search Console.
How to diagnose sitemap index issues
A practical sequence:
— check index accessibility;
— check child URLs;
— check child accessibility;
— check child limits;
— check child validity;
— check Search Console errors;
— check robots.txt.
If the index is valid and accessible but child sitemaps are not read, the issue is likely in child URLs or limits. Fix those and resubmit.
For a broader audit, SEO audit can help verify sitemap, robots.txt and indexing in one place.
How to fix sitemap index issues
Fix steps:
— make the index accessible;
— fix child URLs;
— ensure child sitemaps are valid;
— split large child sitemaps;
— submit the index in Search Console;
— add the index to robots.txt;
— request re-crawl after fixes.
FAQ
Why is my sitemap index not working?
Most often because child sitemap URLs are wrong, child sitemaps exceed limits, are not valid XML, or the index is not accessible.
What is a sitemap index?
It is an XML file that lists other sitemap files. It is used for large sites that exceed the limits of a single sitemap.
How many URLs can a child sitemap have?
Up to 50,000 URLs and 50 MB per file. If larger, split further.
Can child sitemaps use relative URLs?
No. Child sitemap URLs must be absolute.
Should the sitemap index be listed in robots.txt?
Yes. It helps Google find the index faster.
How long does it take for Google to read a sitemap index?
It can take days or weeks. Submitting in Search Console speeds up the process.
What if only some child sitemaps are read?
Check those child sitemaps for errors, limits or accessibility issues. Fix and resubmit.
Can a sitemap index point to another sitemap index?
No. Sitemap index can only point to sitemap files, not to other indexes.
Does sitemap index guarantee indexing?
No. It helps discovery, but Google decides whether to index pages.
What if the sitemap index is not read at all?
Check accessibility, robots.txt and Search Console errors. Ensure the index is submitted and valid.
