Sitemap index files and size limits
One sitemap file tops out at 50,000 URLs or 50 MB. Past that, a sitemap index lists the pieces so search engines can read them all from one address.
| Limit | Value | Source |
|---|---|---|
| URLs per sitemap | 50,000 | sitemaps.org, Google |
| Size per sitemap (uncompressed) | 50 MB (52,428,800 bytes) | sitemaps.org, Google |
| Sitemaps per index | 50,000 | sitemaps.org, Google |
| Index files per site in Search Console | 500 | |
| URL length | under 2,048 characters | sitemaps.org |
| Nesting | An index may not list another index | sitemaps.org |
What an index looks like
<?xml version="1.0" encoding="UTF-8"?>
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<sitemap>
<loc>https://www.example.com/sitemaps/products-1.xml</loc>
<lastmod>2026-09-26</lastmod>
</sitemap>
<sitemap>
<loc>https://www.example.com/sitemaps/blog.xml</loc>
<lastmod>2026-09-20</lastmod>
</sitemap>
</sitemapindex>The format mirrors a normal sitemap: <sitemapindex> replaces <urlset>, and <sitemap> replaces <url>. The optional <lastmod> here is when that sitemap file changed, which lets crawlers skip unchanged files.
How many files will you need?
Which limit bites first?
Drag the sliders. Each file may hold 50,000 URLs and 50 MB uncompressed; whichever you hit first sets the number of files.
4 sitemap files plus one sitemap index, about 6.4 MB each. The 50,000-URL limit decides: at ~150 bytes per entry a full file is only 7.2 MB.
Gzip does not change the arithmetic: Google applies the 50 MB limit to the uncompressed file.
Splitting well
Hitting the limit is the reason to split, but how you split decides how useful Search Console becomes. Google reports submitted and indexed counts per sitemap, so a file per section (products, categories, articles) tells you which part of the site has an indexing problem. The sitemap splitter can split by count or by top-level section and writes the index for you.
- Keep the index and its sitemaps on the same host, with sitemaps in the index’s folder or below.
- Reference the index in robots.txt (
Sitemap: https://www.example.com/sitemap-index.xml) and submit it in Search Console. - Gzip is allowed (
.xml.gz) and saves bandwidth, but the 50 MB limit applies to the uncompressed size. - Validate each child with the sitemap checker; one broken child doesn’t break the others, but it will be reported.
Questions
What is a sitemap index?
A sitemap index is an XML file that lists other sitemap files instead of page URLs. Its root element is <sitemapindex>, and each child is a <sitemap> with a <loc> and optional <lastmod>. You submit the index once and search engines read every sitemap it lists.
How many URLs can a sitemap have?
Up to 50,000 URLs and 50 MB (52,428,800 bytes) uncompressed per sitemap file, under the sitemaps.org protocol, which Google follows.
How many sitemaps can an index list?
Up to 50,000 sitemaps per index file, and the index file itself has the same 50 MB limit. Google lets you submit up to 500 sitemap index files per site in Search Console.
Can a sitemap index contain another sitemap index?
No. An index may only list sitemap files, not other index files. If you need more than 50,000 sitemaps, submit several index files.
Do the files have to be in the same folder?
Google requires the sitemaps listed in an index to be on the same site as the index, and in the same directory or lower, unless you use cross-site submission set up in Search Console.