GZip response on IIS Express

I want to compress responses coming from my IIS Express driven web application. We’re using IIS Express as local development webserver and IIS on staging and on our build machines. I have found many guides on enabling gzipped responses on IIS but none for IIS Express. Is it even possible?

Answers:

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Method 1

You can enable compression in IIS Express, just like for IIS.

1. Start command prompt and go to IIS Express installation folder (%PROGRAMFILES%IIS Express)
2. Run following command

appcmd set config -section:urlCompression /doDynamicCompression:true

To add compression for JSON run the following two commands from the IIS Express installation directory:

appcmd set config /section:staticContent /+[fileExtension=’.json’,mimeType=’application/json’]

appcmd.exe set config -section:system.webServer/httpCompression /+”dynamicTypes.[mimeType=’application/json’,enabled=’True’]” /commit:apphost

Make sure to restart IIS Express.

Method 2

For Visual Studio 2019 I found the above does not work, as the applicationhost.config file is unique to the project. This file is stored in .vs<solution_name>configapplicationhost.config. For VS 2017 it isnt in the solution subfolder.

Thus the solution for me was to replace <httpCompression/> with the following.

<httpCompression directory="%TEMP%iisexpressIIS Temporary Compressed Files">
            <scheme name="gzip" dll="%IIS_BIN%gzip.dll" />
            <dynamicTypes>
                <add mimeType="text/*" enabled="true" />
                <add mimeType="message/*" enabled="true" />
                <add mimeType="application/x-javascript" enabled="true" />
                <add mimeType="application/javascript" enabled="true" />
                <add mimeType="application/json" enabled="true" />
                <add mimeType="*/*" enabled="false" />
            </dynamicTypes>
            <staticTypes>
                <add mimeType="text/*" enabled="true" />
                <add mimeType="message/*" enabled="true" />
                <add mimeType="application/javascript" enabled="true" />
                <add mimeType="application/atom+xml" enabled="true" />
                <add mimeType="application/xaml+xml" enabled="true" />
                <add mimeType="image/svg+xml" enabled="true" />
                <add mimeType="*/*" enabled="false" />
            </staticTypes>
        </httpCompression>

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0