IIS Brotli is currently free of charge and provided "as is". If you encounter any difficulties, please let us know at For priority support or SLA enquiries please contact us through


Installation details are found on the documentation page.


  • Brotli encoding is currently only requested by browsers for https requests, to avoid trouble with bad intermediaries (proxies).
  • Dynamically generated content needs it's Content-Type header to be set in order to be compressed.

Brotli browser support

  • Firefox: 44+ (on by default)
  • Chrome: 49+ (not by default, but can be enabled)
  • Edge: 15+ (on by default)

Known issues

Installation as compression scheme doesn't work on IIS 8.5 and above, so installation as transforming module is required here (this is handled by the installer).


A successfull test with one of the supporting browsers should show an accept-encoding:br in the request headers and subsequently a content-encoding:br in the response headers from the server.

Use the KeyCDN Brotli test tool to check whether Brotli compression is enabled on your website.


v1.1 initial release
v1.1.1 added compression scheme support
v1.1.2 truncation bug fixed, added installer