Accept-Encoding headers being sent by browser but not received by server

I have been trying to debug this for weeks. All of the browsers on all of the clients on my home network are sending 'Accept-Encoding: gzip,deflate'. However, that header is somehow, somewhere being dropped before the request makes it to a web server. For example, http://www.whatsmyip.org/http_compression/ says 'No, your browser is not requesting compressed content'.

I've used Fiddler to make sure that all of my browsers are indeed sending the heade开发者_开发问答r. I've swapped out my router. I've turned off all anti-virus software.

Brighthouse/Roadrunner (the local cable ISP) says they are not doing any filtering (and I can't see why they would in this case).

Any suggestions would be most welcome!

Try it with HTTPS.

If you are browsing a site via HTTPS, nothing between your browser and the web server can alter any HTTP-level aspect of the the request or response, including whether compression is enabled, without you having immediate and clear knowledge of that fact (check the site's certificate in your browser address bar and see if it's legit).

I had the Accept-Xncoding issue and determined it was CA Internet Security Suite causing the issue. Disabling wan't enought, you had to uninstall and then clear IE Cache.

Check your antivirus software. It's probably intercepting your outbound traffic and modifying headers on the fly in order to get uncompressed content. Lazy programmers don't like to include decompression methods themselves, or deal with chunked encoding.

Norton Internet Security will overwrite accept encoding with this line:

---------------: ----- -------

McAfee overwrites with this:

X-McProxyFilter: *************

something I haven't identified yet overwrites with this:

Accept-Xncoding: gzip, deflate

You are probably in the same boat. I read Zone Alarm wipes out the encoding header entirely (which means recalculating the size of the packet, but why should they care how much load they introduce on your system?). If you're running Zone Alarm, turn off the 'internet privacy option' or whatever it is, and try again.

Everytime I've seen this problem, it has been the result of shitty antivirus. Completely disabling someone's ability to receive compressed content without letting them know is dirty.