What 'Content-Type' header to use when serving gzipped files?
Solution 1:
Compressed content in the response is indicated in the Content-Encoding. The Content-Type should remain the same, that is, it should reflect the underlying media type that is compressed.
Content-Type: application/javascript
Content-Encoding: gzip
See sections 14.11 Content-Encoding and 3.5 Content Codings of RFC 2616 for more information.