DecompressionStream: readable property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨May 2023⁩.

Note: This feature is available in Web Workers.

The readable read-only property of the DecompressionStream interface returns a ReadableStream that emits decompressed data as Uint8Array chunks.

This example creates a DecompressionStream that performs gzip decompression. It writes some compressed binary data to the writable stream, then reads the decompressed data from the readable stream, decoding it as UTF-8 text.

const stream = new DecompressionStream("gzip");

// Write data to be compressed
const data = Uint8Array.fromBase64(
  "H4sIAAAAAAAAE/NIzcnJ11Eozy/KSVEEAObG5usNAAAA",
);
const writer = stream.writable.getWriter();
writer.write(data);
writer.close();

// Read compressed data
const reader = stream.readable.getReader();
let done = false;
let output = [];
while (!done) {
  const result = await reader.read();
  if (result.value) {
    output.push(...result.value);
  }
  done = result.done;
}
console.log(new TextDecoder().decode(new Uint8Array(output))); // Hello, world!