Google and Bing announced that they have enhanced sitemaps file size from 10MB to 50MB. But 50,000 URL limit has not changed. That’s mean the uncompressed version must now be below 50MB, no longer below 10MB.
While this time most of sitemaps are under 10MB file limit, after sometimes our systems exceeding this limit. Most often this is reason when sitemap files list very long URLs or if they have merits listing long extra URLs (as optional language URLs, Image URLs, etc), which increased the size of the sitemap file.”
Here is Google’s tweet on 30 November morning:
We’ve updated the Sitemaps protocol with Bing! Sitemaps & indexes can be considerably larger now. More at https://t.co/uygpuywUEh
— Google Webmasters (@googlewmc) 30 November 2016