audio-decode

Decode any audio format to raw samples. JS / WASM – no ffmpeg, no native bindings, works in both node and browser. Small API, minimal size, near-native performance, lazy-loading, chunked decoding.

import decode from 'audio-decode';

const { channelData, sampleRate } = await decode(anyAudioBuffer);

Supported formats

| Format | Package | Size | Engine | |--------|---------|------|--------| | MP3 | @audio/decode-mp3 | 92 KB | WASM | | WAV | @audio/decode-wav | 4 KB | JS | | OGG Vorbis | @audio/decode-vorbis | 164 KB | WASM | | FLAC | @audio/decode-flac | 133 KB | WASM | | Opus | @audio/decode-opus | 178 KB | WASM | | M4A / AAC | @audio/decode-aac | 368 KB | WASM | | QOA | @audio/decode-qoa | 8 KB | JS | | AIFF | @audio/decode-aiff | 20 KB | JS | | CAF | @audio/decode-caf | 7 KB | JS | | WebM | @audio/decode-webm | 263 KB | WASM | | AMR | @audio/decode-amr | 241 KB | WASM | | WMA | @audio/decode-wma | 91 KB | WASM |

Whole-file

Auto-detects format. Input can be ArrayBuffer, Uint8Array, or Buffer.

import decode from 'audio-decode'

let { channelData, sampleRate } = await decode(buf)

Chunked

let dec = await decode.mp3()
let a = await dec(chunk1)    // { channelData, sampleRate }
let b = await dec(chunk2)
await dec()                  // close

Streaming

import decode from 'audio-decode'

for await (let { channelData, sampleRate } of decode.mp3(response.body)) {
  // process chunks
}

Works with ReadableStream, fetch body, Node stream, or any async iterable.

Formats: mp3, flac, opus, oga, m4a, wav, qoa, aac, aiff, caf, webm, amr, wma.

Browser

Each codec is a self-contained bundle under @audio/* — no transitive deps, no import map bloat. For selective loading in the browser (avoids bundling all codecs):

<script type="importmap">
{
  "imports": {
    "audio-decode": "https://esm.sh/audio-decode",
    "audio-type": "https://esm.sh/audio-type",
    "@audio/decode-mp3": "https://esm.sh/@audio/decode-mp3",
    "@audio/decode-wav": "https://esm.sh/@audio/decode-wav",
    "@audio/decode-flac": "https://esm.sh/@audio/decode-flac",
    "@audio/decode-opus": "https://esm.sh/@audio/decode-opus",
    "@audio/decode-vorbis": "https://esm.sh/@audio/decode-vorbis",
    "@audio/decode-aac": "https://esm.sh/@audio/decode-aac",
    "@audio/decode-qoa": "https://esm.sh/@audio/decode-qoa",
    "@audio/decode-aiff": "https://esm.sh/@audio/decode-aiff",
    "@audio/decode-caf": "https://esm.sh/@audio/decode-caf",
    "@audio/decode-webm": "https://esm.sh/@audio/decode-webm",
    "@audio/decode-amr": "https://esm.sh/@audio/decode-amr",
    "@audio/decode-wma": "https://esm.sh/@audio/decode-wma"
  }
}
</script>
<script type="module">
  import decode from 'audio-decode'
  let { channelData, sampleRate } = await decode(buf)
</script>

Only list the codecs you need — each @audio/decode-* package bundles all its WASM/JS deps internally.

Metadata

Read tags, pictures, markers and regions without decoding samples. Available for wav, mp3, flac.

import { wav, mp3, flac } from 'audio-decode/meta'

let { meta, sampleRate, markers, regions } = mp3(bytes)
// meta: { title, artist, album, year, bpm, key, comment, pictures, raw, ... }
// markers: [{ sample, label }]
// regions: [{ sample, length, label }]

Each codec sub-package also exposes its parser directly:

import { parseMeta } from '@audio/decode-wav/meta'
let info = parseMeta(wavBytes)

WebWorker

Each @audio/decode-* package is a self-contained ESM module — import directly in a worker:

// decode-worker.js
import decode from '@audio/decode-mp3'

self.onmessage = async ({ data }) => {
  let pcm = await decode(data)
  self.postMessage(pcm, pcm.channelData.map(ch => ch.buffer))
}

// main.js
let worker = new Worker('./decode-worker.js', { type: 'module' })
worker.postMessage(mp3buf, [mp3buf])
worker.onmessage = ({ data }) => { /* { channelData, sampleRate } */ }

See also

• audio-encode – encode PCM into any audio format.
• audio-type – detect audio format from buffer.