A sitemap index is an XML file that lists several individual sitemaps. It groups the sitemaps of a large website under one address, so you can submit them to Search Console in a single step.
Structure and limits
A single sitemap may contain at most 50,000 URLs and be 50 MB uncompressed. If a site needs more, the URLs go into several sitemap files and the index points to them. The index file itself may list up to 50,000 sitemaps and also has a 50 MB limit. It must be UTF-8 encoded.
Required elements are the root sitemapindex, one sitemap element per entry, and loc with the address of each sitemap. The lastmod element is optional and gives the time that sitemap file was last modified, not the dates of the pages inside it.
Under the protocol, an index can only list sitemaps on the same site. Google adds that these sitemaps must sit in the same directory as the index or deeper, unless cross-site submission is set up. Google allows up to 500 sitemap index files for each site in a Search Console account.
| Type | Purpose | Limits | Required elements |
|---|---|---|---|
| XML sitemap | a file with information about the pages, videos and other files on a site and the relationships between them | at most 50,000 URLs or 50 MB (uncompressed) per file; UTF-8, absolute URLs | urlset, and per URL a url with loc |
| Sitemap index (this term) | groups several sitemaps so they can be submitted together | at most 50,000 sitemaps and 50 MB per index; up to 500 index files per site in Search Console | sitemapindex, and per sitemap a sitemap with loc |
| Image sitemap | tells Google about images it might not otherwise find, such as images loaded with JavaScript | up to 1,000 image:image per url; otherwise as for XML sitemaps | image:image with image:loc |
| Video sitemap | adds information about videos hosted on the pages | as for XML sitemaps; description at most 2,048 characters | video:video with video:thumbnail_loc, video:title, video:description and either video:content_loc or video:player_loc |
| News sitemap | tells Google about news articles with extra details | up to 1,000 news:news per file; only articles from the last two days | news:news with news:publication (news:name, news:language), news:publication_date, news:title |
| Sitemap with hreflang | lists the language and regional versions of a page | as for XML sitemaps | per url a loc and one xhtml:link rel="alternate" hreflang="…" for every version, including the page itself |
| HTML sitemap | a page of links for visitors to the site | – (not part of the sitemap protocol; Google says it cannot be submitted as a sitemap. Source: Google Search Central Blog, 2005) | – |
Image, video, news and hreflang data are extensions of the XML format; every file is limited to 50,000 URLs or 50 MB. Of the optional elements, Google uses lastmod if it is consistently and verifiably accurate and ignores priority and changefreq. The HTML sitemap details come from a 2005 Google blog post; Google's current sitemap documentation does not mention HTML sitemaps. Sources: Google Search Central: Build and submit a sitemap (last updated 2025-12-10); Google Search Central: Manage your sitemaps with sitemap index files; Google Search Central: Image sitemaps; Google Search Central: Video sitemaps; Google Search Central: Create a news sitemap; Google Search Central: Localized versions of your pages (sitemap method); sitemaps.org: Sitemaps XML format; Google Search Central Blog (2005): How is a Google Sitemap different from an HTML sitemap?. Last checked: .
Example
<?xml version="1.0" encoding="UTF-8"?>
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<sitemap>
<loc>https://www.example.com/sitemap-products.xml</loc>
<lastmod>2026-10-01</lastmod>
</sitemap>
<sitemap>
<loc>https://www.example.com/sitemap-blog.xml</loc>
</sitemap>
</sitemapindex>
Sources
- sitemaps.org protocol – Sitemap index filesitemaps.org
- Manage your sitemaps with a sitemap index file – Google Search Centraldevelopers.google.com
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