# IIS7 is gzipping files but not serving the gzipped version

By following a number of helpful blog posts I have configured IIS to gzip my static files. I have even enabled Failed Request Tracing and filtered to the 200 status code, and I can see the successful compression events taking place as well as the finished headers, which look like this:

Headers="Content-Type: text/css
Content-Encoding: gzip
Last-Modified: Mon, 04 Oct 2010 17:35:08 GMT
Accept-Ranges: bytes
ETag: "02ef37cea63cb1:0"
Vary: Accept-Encoding
Server: Microsoft-IIS/7.5
X-Powered-By: ASP.NET
"


However, when I test in Fiddler and Firefox the Content-Encoding header is missing, and the file is not gzipped.

This is a similar issue to this question which was never resolved.

IIS is generating the gzipped files which I can see in C:\inetpub\temp\IIS Temporary Compressed Files .

Does anyone know how I can troubleshoot this?

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Please see my answer to this question. It may help: serverfault.com/questions/505788/… –  ianbeks Jul 23 at 9:29