audio-encode [](https://github.com/audiojs/audio-encode/actions/workflows/test.js.yml)

June 22, 2026 · View on GitHub

Encode raw audio samples to any format.
JS / WASM – no ffmpeg, no native bindings, works in both node and browser.
Small API, minimal size, near-native performance, stream encoding.

import encode from 'encode-audio';

const buf = await encode.wav(channelData, { sampleRate: 44100 });

Supported formats:

Format	Package	Engine
WAV	@audio/encode-wav	JS
MP3	@audio/encode-mp3	WASM
OGG Vorbis	@audio/encode-ogg	WASM
Opus	@audio/encode-opus	WASM
WebM	@audio/encode-webm	WASM (Opus)
FLAC	@audio/encode-flac	WASM
AAC	@audio/encode-aac	WebCodecs*
AIFF	@audio/encode-aiff	JS
CAF	@audio/encode-caf	JS
QOA	@audio/encode-qoa	JS

_{* AAC uses the native WebCodecs AudioEncoder — browser-only (Chromium/Safari), throws in Node.}

Whole-file encode

Specify the format as method name. Input is Float32Array[] (one per channel), a single Float32Array (mono), or an AudioBuffer.

import encode from 'encode-audio';

const wav  = await encode.wav(channelData, { sampleRate: 44100 });
const aiff = await encode.aiff(channelData, { sampleRate: 44100 });
const caf  = await encode.caf(channelData, { sampleRate: 44100 });
const mp3  = await encode.mp3(channelData, { sampleRate: 44100, bitrate: 128 });
const ogg  = await encode.ogg(channelData, { sampleRate: 44100, quality: 5 });
const flac = await encode.flac(channelData, { sampleRate: 44100 });
const opus = await encode.opus(channelData, { sampleRate: 48000, bitrate: 96 });
const webm = await encode.webm(channelData, { sampleRate: 48000, bitrate: 96 });
const qoa  = await encode.qoa(channelData, { sampleRate: 44100 });
const aac  = await encode.aac(channelData, { sampleRate: 44100, bitrate: 128 }); // browser only

encode.formats lists the supported names and encode.mime maps each to a MIME type — handy for format-agnostic pipelines.

Chunked encoding

Call with just options (no data) to create a streaming encoder:

import encode from 'encode-audio';

const enc = await encode.mp3({ sampleRate: 44100, bitrate: 128 });

const a = await enc(chunk1);  // Uint8Array
const b = await enc(chunk2);
const c = await enc(null);        // end of stream — flush + free

// explicit control: enc.flush(), enc.free()

Options

Option	Description	Applies to
`sampleRate`	Output sample rate (required)	all
`bitrate`	Target bitrate in kbps	mp3, opus, webm, aac
`quality`	Quality 0–10 (VBR)	ogg, mp3
`channels`	Output channel count	all
`bitDepth`	Bit depth: 16/24/32 (wav), 16/24 (aiff, flac), 16/32 (caf)	wav, aiff, flac, caf
`compression`	FLAC compression level 0–8	flac
`application`	`'audio'`, `'voip'`, or `'lowdelay'`	opus, webm
`meta`	Tags (see below)	wav, mp3, flac, aiff, ogg, opus

Metadata

Pass meta (and, for wav, markers/regions) straight to the encoder:

let bytes = await encode.flac(channelData, {
  sampleRate: 44100,
  meta: { title: 'Hare Krishna', artist: 'Prabhupada', year: '1966' }
})

Tags work for wav, mp3, flac, aiff, ogg and opus. Cue markers and regions are wav-only. opus bakes tags into the OpusTags header at encode time (stays fully streaming); the others splice tags into the finished file — so passing meta to a streaming/chunked encode of wav/mp3/flac/aiff/ogg buffers the output and emits it on flush.

You can also tag already-encoded bytes via encode-audio/meta:

import { wav } from 'encode-audio/meta'

let out = wav(bytes, {
  meta: { title: 'Hare Krishna', artist: 'Prabhupada', year: '1966' },
  markers: [{ sample: 44100, label: 'verse' }],
  regions: [{ sample: 88200, length: 44100, label: 'chorus' }]
})

Each codec sub-package also exposes its writer directly:

import { writeMeta } from '@audio/encode-mp3/meta'
let tagged = writeMeta(mp3Bytes, { meta: { title: 'foo' } })

License

MIT

ॐ