XML sitemap size limits: Crawl Audit check 33

Short answer: a single sitemap file can hold at most 50,000 URLs and 50MB uncompressed. Bigger sites split their URLs across several sitemaps and list those in a sitemap index. Check 33 warns about the size limit only, and only when your server reports the file size. Most small business sites are nowhere near either limit.

What Crawl Audit checks

• Pass: the sitemap's Content-Length header is under 50MB, or the header isn't sent.
• Fail: it's 50MB or more.
• Warning: there's no sitemap to measure (see check 32).

Two limits of the check itself, so you know what a pass means. It reads the size from the response header, so a sitemap sent compressed or without a Content-Length passes without being measured. And it doesn't count URLs, which is the limit a large shop usually hits first.

The real limits

• Google: "All formats limit a single sitemap to 50MB (uncompressed) or 50,000 URLs. If you have a larger file or more URLs, you must break your sitemap into multiple sitemaps."
• The sitemaps protocol: "no more than 50,000 URLs and must be no larger than 50MB (52,428,800 bytes)."
• Compression: "you may compress your Sitemap files using gzip ... however the sitemap file once uncompressed must be no larger than 50MB."

For scale: our sitemap is about 60KB for 334 URLs, roughly 180 bytes a URL. At that rate you'd hit the 50,000-URL limit long before the 50MB one.

Sitemap index files

When you split a sitemap, a sitemap index lists the pieces. Google says "A sitemap index file may have up to 50,000 loc tags", and you "can submit up to 500 sitemap index files for each site in your Search Console account." Submit the index, and Google finds the rest.

On your platform

• WordPress: core's /wp-sitemap.xml and Yoast's /sitemap_index.xml are both sitemap index files that point to smaller sitemaps.
• Shopify, Wix and Squarespace: the platform generates and splits the sitemap for you.
• Next.js: for large sites, split with generateSitemaps in your sitemap file.

Sources

• Google Search Central, Build and submit a sitemap and Manage large sitemaps, checked 3 October 2026.
• sitemaps.org, Sitemaps XML format.
• Next.js, sitemap.xml.