IIS application missing Content-Encoding - gzip in Response Header

Question

In Firebug the request header has the following entry:
Accept-Encoding: gzip, deflate

But there\'s no:
Content-Encoding: gzip

Answer 1

I have similar situation with IIS and gzip configuration

In Firebug the request header has the following entry: Accept-Encoding: gzip, deflate

But there's no: Content-Encoding: gzip In the Response Header.

In my case problem was with antivirus protection. Actually gzipping was applied but antivirus with enabled settings protect http connections (depends on concrete program), unzip response check it and after that rewrite response headers on the fly.

NOTE: A key attribute when some proxy/antivirus changed your response headers, it is when disappear Content-Length and Transfer-Encoding is added with value chunked.