Internet explorer - issues with gzip/deflate (seeking confirmation)

Question

I have come accross something very strange whilst trying to use deflate, I am a bit out of my depth but this has become something of an obsession which I am determined to get to the bottom of.

Essentially I have spent the last two weeks trying to get my website to compress using deflate. Everything was working fine in Firefox, but when I inspected the network traffic in IE dev tools the site was showing all files as uncompressed.

Maybe another IE Fail - Well yes and no. If i use user agent switcher plugin for firefox it also appears that the files are not being compressed in firbug network traffic.

Content encoding is missing from the IE response headers also.

If I look at the network traffic through wireshark I can see that the files appear to be compressed when viewed through both browsers but are compressed to a greater extent when viewed through firefox.

Finally, stranger still, if I look through my server logs the files show exactly the same compressed size.

Has anyone else seen similar issues with gzip/deflate and IE. Can anyone explain what is happening here?

Answer 1

Check it in Fiddler ( www.fiddlertool.com ). That way the results are browser agnostic but presented in a more usable format than wireshark.

I don't have IE9 on this computer to check, but I've heard that it doesn't show compression correctly.