Specify multiple (gzip + brotli) httpCompression schemes in IIS7/8/8.5 and prioritise brotli

Question

I\'m trying to get the new Brotli compression scheme working in IIS using "Brotli compression module for Microsoft IIS" by iisspeed.com.

The Brotli compression

Answer 1

From your second link (emphases mine):

HcPriority is removed as scheme to use when multiple ones appear in Accept-Encoding header of request is picked depending on scheme which is appear first in Accept-Encoding header (assuming no q factor). This is as per HTTP specs.

Also discussed here: HTTP: What is the preferred Accept-Encoding for “gzip,deflate”?

If you make make the same request with Accept-Encoding: br, gzip, deflate, via an HTTP client that allows you to manually set the request headers (e.g. Postman or Fiddler) or a browser extension that allows you to change the request headers (e.g. ModHeader for Chrome), you should see the response encoded with Brotli even when gzip and/or deflate are available.

EDIT: I was able to get the Brotli module to work as desired (i.e. use Brotli encoding when it is tied for the most-preferred regardless of ordering in Accept-Encoding) by registering it as a global native module and ordering it before both the dynamic and static compression modules.