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?