I did some tests for my web app and I came to the conclusion that zstd -19 gave me the best results for small file sizes and fast decompression of text data.

It's amazing that you can include a 50kb zstd decompression wasm module and really speed everything up. In comparison gzip via compression streams were pretty slow and not great compression. I would've gone with brotli decompression streams but those don't seem to be widely supported yet.

If you don't like wasm, there's even an 8kb pure JavaScript decompressor that's a bit slower. But since I like to write in C it's just better all around to write my app in c and have the decompressor compiled directly in.