Q: Where do I place my Sitemap?
It is strongly recommended that you place your Sitemap at the root directory of your HTML server; that is, place it at //example.com/sitemap.xml. In some situations, you may want to produce different Sitemaps for different paths on your site — e.g., if security permissions in your organization compartmentalize write access to different directories.
Q: How big can my Sitemap be?
Sitemaps should be no larger than 10MB (10,485,760 bytes) and can contain a maximum of 50,000 URLs. These limits help to ensure that your web server does not get bogged down serving very large files. This means that if your site contains more than 50,000 URLs or your Sitemap is bigger than 10MB, you must create multiple Sitemap files and use a Sitemap index file. You should use a Sitemap index file even if you have a small site but plan on growing beyond 50,000 URLs or a file size of 10MB. A Sitemap index file can include up to 1,000 Sitemaps and must not exceed 10MB (10,485,760 bytes). You can also use gzip to compress your Sitemaps.
Q: My site has tens of millions of URLs; can I somehow submit only those that have changed recently?
You can list the URLs that change frequently in a small number of Sitemaps and then use the lastmod tag in your Sitemap index file to identify those Sitemap files. Search engines can then incrementally crawl only the changed Sitemaps.
Q: What do I do after I create my Sitemap?
Once you have created your Sitemap, let search engines know about it by submitting directly to them, pinging them, or adding the Sitemap location to your robots.txt file.
Q: Do URLs in the Sitemap need to be completely specified?
Yes. You need to include the protocol (for instance, http) in your URL. You also need to include a trailing slash in your URL if your web server requires one. For example, //www.example.com/ is a valid URL for a Sitemap, whereas www.example.com is not.
Q: Does position of a URL in a Sitemap influence its use?
No. The position of a URL in the Sitemap is not likely to impact how it is used or regarded by search engines.