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 header. 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!