Optimal number of URLs in sitemaps URLset

Question

I’m trying to find the best approach to create my sitemap (I deal with a huge number of URLs).

I have an XML Sitemap with a tree-structure, it’s composed of many sitemap.xml. Actually I have max 1000 URLs for each sitemap.xml.

What's the optimal number of urls for each sitemap.xml? Does Google prefers a larger number of URLs (greater than 1000), or less URLs distributed in more XML files?

Answer 1

I was experiencing the exact same issue, I dealt with 80k+ URLs in my WordPress website.

Previously I was providing 5000 URLs in each sitemap. It was resoursce hunger & Google was not crawling it suffecinotly. Then I made 2000 URLs each sitemap then crawling rate became somewhat okay. Then I decided to make 1000 URLs each sitemap & within 2 days my crawling rate became very good. within 10 days 95% of the URLs were indexed.

So, I would say go with 1000 or lower.

Answer 2

From the sitemaps.org protocol specification:

You can include up to 50,000 URLs in each Sitemap file:

[…] each Sitemap file that you provide must have no more than 50,000 URLs and must be no larger than 10MB (10,485,760 bytes)

[…]

If you want to list more than 50,000 URLs, you must create multiple Sitemap files.

You can link up to 50,000 Sitemap files in each Sitemap index file:

Sitemap index files may not list more than 50,000 Sitemaps and must be no larger than 10MB (10,485,760 bytes) […]

You can have multiple Sitemap index files (no limit stated):

You can have more than one Sitemap index file.