Cloudflare does not support brotli at all for now. The worst thing is: Cloudflare would modify Accept-Encoding header in any HTTP request so my server could not see it. Almost all modern browsers send
Accept-Encoding: gzip, deflate, br, but Cloudflare completely rewrite it. Although my server is serving brotli files, it will get a wrong HTTP header.
At least, I wish Cloudflare could bypass
Accept-Encoding, so a server could send back the correct file.
Brotli is a compression format which is supported by most modern browsers. Google and many websites use it to minimize static files.
In fact, Cloudflare has implemented brotli for nginx a year ago: