This is NOT possible. The reason is the way the Fetch API works.

The fetch method returns a Promise; the Promise API uses a then method to which you can attach “success” and “failure” callbacks. Therefore, you can gain access to progress.

Still, don't lose hope! There is a workaround that can do the trick (I found it on github repository of the Fetch API):

you can convert the request to a stream request and then when a response return is just a bitarray of the file content. then you need to collect all of the data and when its end decode it to the file you want

function consume(stream, total = 0) {

  while (stream.state === readable) {

    var data = stream.read()

    total += data.byteLength;

    console.log(received  + data.byteLength +  bytes ( + total +  bytes in total).)

  }

  if (stream.state === waiting) {

    stream.ready.then(() => consume(stream, total))

  }

  return stream.closed

}

fetch(/music/pk/altes-kamuffel.flac)

  .then(res => consume(res.body))

  .then(() => console.log(consumed the entire body without keeping the whole thing in memory!))

  .catch((e) => console.error(something went wrong, e))