Enable HTTP Compression in IIS Express

Open a Command Prompt as Administrator.  Go to the IIS Express installation folder

• 32 bit : cd %programfiles%\iis express 
• 64 bit: cd %programfiles(x86)%\iis express

Run the following command to enable dynamic compression:

appcmd set config -section:urlCompression /doDynamicCompression:true

You should see the following message:

 Applied configuration changes to section "system.webServer/urlCompression" for "MACHINE/WEBROOT/APPHOST" at configuration commit path "MACHINE/WEBROOT/APPHOST"

 Now add the mime-types to compress.  I'm using wildcard entries.  Static types first:

appcmd set config /section:httpCompression /staticTypes.[mimeType='*/*'].enabled:"true" /commit:apphost

You should see the following message:

Applied configuration changes to section "system.webServer/httpCompression" for "MACHINE/WEBROOT/APPHOST" at configuration commit path "MACHINE/WEBROOT/APPHOST"

Now for the dynamic types:

 appcmd set config /section:httpCompression /dynamicTypes.[mimeType='*/*'].enabled:"true" /commit:apphost

And the final message you should see:

 Applied configuration changes to section "system.webServer/httpCompression" for "MACHINE/WEBROOT/APPHOST" at configuration commit path "MACHINE/WEBROOT/APPHOST"

Reference: http://www.iis.net/configreference/system.webserver/httpcompression