It seems to me, that mod_deflate in Apache 2.2 will always return:

Content-Encoding: gzip

and never:

Content-Encoding: deflate

It was explained to me, that although there may be a deflate algorithm, mod_deflate is named after a file-format, in which the algorithm could be any of:

gzip, bzip. pkzip

Of those three, mod_deflate provides gzip.

It seems as though gzip is the most popular and widely-supported algorithm in web browsers, but I know some web servers and proxies do return Content-Encoding: deflate.

Aside from the confusion of the module's name, it true that mod_deflate will only return Content-Encoding: gzip?

Thank you.


I believe both the encodings compress to the same extent. Unless there's some special purpose for which you need only deflate, I don't see any reason why you specifically want deflate to be used instead of gzip.

There may be some performance differences. If yes, please enlighten me.


Yes. From what I've read in the Apache docs and from people in the Apache httpd project i've talked to, mod_deflate will only ever return gzipped content.

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