Compressed XML sitemaps are supported by all major search engines. The benefit of
compressed sitemaps is that they save bandwidth for website servers and search engines.
That is why some sitemaper generators such as
A1 Sitemap Generator
support generating sitemaps using GZip compression. Usually such sitemap files
end with file extesion
.gz or
.xml.gz.
If you try download your own sitemap files, most webbrowser will correctly prompt for you to download
the compressed sitemap file such as
example.xml.gz.
However, if your webserver is not sending correct MIME headers for .gz files,
some browsers may instead try open the sitemap file. This will fail as the internet browser has not correctly recognized the file format.
Under all circumstances, if you submit your XML sitemap to search engines like Google, chances are they will be
able to correctly download and process your XML sitemaps no matter if they are compressed or not.
If you get error messages, you can always return to using normal uncompressed XML sitemaps.
