Why Brotli?

Brotli is supported on most modern browsers. For browsers that don't support Brotli, the compression method will fall back to gzip or deflate based on the request's Accept-Encoding header. Enabling Brotli compression is an easy performance win.

Brotli is usually more effective at compressing compared to gzip and deflate. When I enabled Brotli compression for Highlight, I saw response sizes decrease around 40% with no latency increases (for the most part requests were faster!).

The Code Changes

Installing Dependencies

# Install the Chi, older versions of Chi don't support Brotli
go get -u github.com/go-chi/chi

# Install the package that will do the Brotli compression
go get -u gopkg.in/kothar/brotli-go.v0

Enabling Brotli Compression

r := chi.NewMux()
// /* means to compress all content types that can be compressed.
compressor := middleware.NewCompressor(5, "/*")
compressor.SetEncoder("br", func(w io.Writer, level int) io.Writer {
	params := brotli_enc.NewBrotliParams()
	params.SetQuality(level)
	return brotli_enc.NewBrotliWriter(params, w)
})
r.Use(compressor.Handler)

The "/*" means to compress all content types that can be compressed. These are the supported types:

var defaultCompressibleContentTypes = []string{
	"text/html",
	"text/css",
	"text/plain",
	"text/javascript",
	"application/javascript",
	"application/x-javascript",
	"application/json",
	"application/atom+xml",
	"application/rss+xml",
	"image/svg+xml",
}

That's it, congrats on the easy performance win for you and your users!