Sitemap Index File

A sitemap index file points search engines to multiple sitemap files. It becomes useful when a website has more URLs than should fit into one sitemap or when different content groups have separate sitemaps. For example, a large multi-location service provider might maintain distinct sitemap files for services, articles, and locations. An index is not the same as an individual XML sitemap: it organizes the sitemap files rather than directly listing every page. Google publishes size and URL limits for sitemaps, and search engines still decide what to crawl and index. A sitemap index is unnecessary complexity for many small service websites.