GZIP is a software application used for file compression.The Content-Encoding header in HTTP/1.1 allows clients to optionally receive compressed HTTP responses and (less commonly) to send compressed requests. The standard itself specifies two compression methods: GZIP and Deflate. Compressed responses are supported by many HTTP client libraries, almost all modern browsers and both of the major HTTP server platforms, Apache and Microsoft IIS.
For Last Mile, Private Last Mile, and Mobile tests, you can specify Additional HTTP Headers in the test settings for GZIP encoding control.
This setting is not available for Backbone tests.