Question

Internet explorer 6 VS1 doesn’t support gzip compression correctly.
It does however understand deflate.
Is it sufficient to change the scheme name in applicationhost.config from gzip to deflate to fix this issue?
Are there any downsides to using deflate instead of gzip?

<!-- c:\windows\system32\inetsrv\config\applicationhost.config -->
<httpCompression directory="%SystemDrive%\inetpub\temp\IIS Temporary Compressed Files">
    <!-- changed name="gzip" to name="deflate" -->
    <scheme name="deflate" dll="%Windir%\system32\inetsrv\gzip.dll" />
    <dynamicTypes>
        [...]
    </dynamicTypes>
    <staticTypes>
        [...]
    </staticTypes>
</httpCompression>

Related links:

• Deflate compression browser compatibility and advantages over GZIP
• http://www.vervestudios.co/projects/compression-tests/
• http://en.wikipedia.org/wiki/Internet_Explorer_6
• http://msdn.microsoft.com/en-us/library/ms690689(v=VS.90).aspx
• http://www.iis.net/ConfigReference/system.webServer/httpCompression
• http://support.microsoft.com/kb/837251

Answer 1

It doesn’t seem to solve the problem. Internet explorer 6 VS1 doesn’t support gzip nor deflate. 🙁

At least not when using dynamic compression on iis.