# How do sitemap errors help diagnose technical SEO problems?

> A sitemap can function as a controlled test set.

If your sitemap contains 100,000 URLs and only 50,000 are indexed, investigate:

- duplicates;

- canonical mismatches;

- noindex;

- content quality;

- discovery;

- URL status;

- rendering.

Do not interpret the indexed/submitted ratio as a universal "indexation score." The reasons vary by site.

## Sources

- [Google Search Central — Overview](https://developers.google.com/search/docs/crawling-indexing/sitemaps/overview)

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Answered by Abhinav Krishna (https://www.theseocentral.com/author/abhinav-krishna)
Source: https://www.theseocentral.com/technical-seo-faq/how-do-sitemap-errors-help-diagnose-technical-seo-problems