Oh wait. It's a redirect to StackOverflow?!
https://stackoverflow.com/questions/23945494/use-html5-to-re...
There are far more knobs you can tune whereas the native browser conversion only has mimetype and quality (via toBlob: https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasE...)
https://raw.githubusercontent.com/brunobar79/J-I-C/master/sr...
Image-conversion is the library I've used the most, since you can target file-size || quality:
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It also does make sense for you to pick and choose only the compression codecs you will need. Otherwise the cost of making every client download huge and unused wasm libraries might outweigh any bandwidth savings from compression.