Steps

To reduce the size of the HTTP responses XWiki sends to the browser, enable gzip compression in Tomcat:

1. Open the TOMCAT_HOME/conf/server.xml file.
2. Locate the <Connector> element used for HTTP traffic.
3. Add or update the following attributes inside the Connector:

   <Connector port="8080"
   ...
   compression="on"
   compressionMinSize="2048"
   compressibleMimeType="text/html,text/xml,text/css,text/javascript,application/json" />

4. Save the server.xml file.
5. Restart the Apache Tomcat server.
6. Open your wiki in a browser and check the "Network" tab of the browser developer tools. The responses served by XWiki now carry a Content-Encoding: gzip header.

FAQ

Which responses are compressed?

Only the MIME types listed in compressibleMimeType, and only responses larger than compressionMinSize bytes. Images and other already-compressed formats are not worth adding.