We know that each XML sitemap file can contain a maximum of 50,000 URLs but what is counted as the 50,000 URLs? John Mueller was asked if Google counts both the location URL and the alternative URL in the 50,000 limits. John said on Twitter it is just the location URL.
As Google documented, “All formats limit a single sitemap to 50MB (uncompressed) and 50,000 URLs. If you have a larger file or more URLs, you will have to break your list into multiple sitemaps. You can optionally create a sitemap index file (a file that points to a list of sitemaps) and submit that single index file to Google. You can submit multiple sitemaps and/or sitemap index files to Google.”
Here is the question and answer on Twitter:
— johnmu of switzerland (personal) (@JohnMu) July 28, 2022
Forum discussion at Twitter.