WebAssembly · libopus 1.6.1

Opus audio for the web platform

Small, modern WebAssembly bindings for libopus raw-packet encode and decode — Discord/WebRTC-ready 48 kHz stereo defaults, Int16 and Float32 PCM, in-band FEC, packet-loss concealment, and a drop-in @discordjs/opus adapter, in browsers and Node.

Quickstart GitHub
npm install libopus-wasm
Browser & Node48 kHz stereoInt16 & Float32In-band FECPacket-loss concealmentDTXVBRdiscord.js adapterSingle-file WASM

Install options & bundlers →

#Try it

libopus-wasm wraps libopus 1.6.1 in a small, single-file WebAssembly module. The default path is realtime voice: 48 kHz, stereo, 20 ms frames, raw Opus packets — no Ogg or WebM container in the way.

import { createEncoder, createDecoder } from "libopus-wasm";

const encoder = await createEncoder(); // 48 kHz, stereo, 20 ms, audio
const decoder = await createDecoder();

const pcm = new Int16Array(960 * 2); // one 20 ms stereo frame
const packet = encoder.encode(pcm);  // -> Uint8Array, a raw Opus packet
const frame = decoder.decode(packet); // -> Int16Array, interleaved PCM

encoder.free();
decoder.free();

The same module runs unchanged in browsers and Node. There is no locateFile hook, no second .wasm request, and no native build step at install time.

#What it does

  • Raw Opus packets. Encode/decode single frames and batches. You own the

    • framing, so it drops straight into WebRTC, Discord, or a custom transport.

  • Browser and Node from one entry. A single-file ES module with the WASM

    • inlined. Bundles cleanly with Vite, webpack, esbuild, and friends.

  • Int16 and Float32 PCM. Use whichever your audio pipeline already speaks.
  • Loss resilience. In-band FEC plus packet-loss concealment for the frames

    • that never arrive.

  • Tunable. Bitrate, VBR/CBR, complexity, signal type, bandwidth, DTX, and a

    • curated CTL passthrough for everything else.

  • Drop-in for @discordjs/opus. A compatibility adapter keeps the same

    • method shape, minus the native toolchain.

#Pick your path

  • Just trying it. Install then Quickstart —

    • a full encode/decode roundtrip in a couple of minutes.

  • Encoding audio. Encoding covers Int16 vs Float32, frame

    • sizes, and batches.

  • Decoding audio. Decoding covers output capacity and

    • variable packet durations.

  • Handling loss. Packet loss walks through FEC and PLC for

    • realtime streams.

  • Inspecting packets. Packet inspection reads a packet's

    • duration, frames, and bandwidth without decoding it.

  • Tuning quality and bitrate. Encoder tuning and the

    • CTL reference.

  • Coming from Discord. discord.js compatibility is a near

    • drop-in for @discordjs/opus.

  • Shipping to the web. Browser usage covers bundlers and Web

    • Audio capture.

  • Looking up a method. The API reference lists every

    • function, option, and constant.

  • Handling failures. Errors & validation explains when a call

    • throws RangeError versus OpusError.

#Project

Wraps libopus 1.6.1 from Xiph.Org. Released under the MIT license; libopus carries its own BSD license, reproduced in THIRDPARTYNOTICES. Source and issues live on GitHub. Not affiliated with Xiph.Org or the Opus authors.