Mp3tag.js

mp3tag.js is an open-sourced JavaScript library used to edit the metadata of audio files. It supports ID3v1, ID3v2.2, ID3v2.3, and ID3v2.4 tags for MP3 files, as well as ID3v2 tags in MP4/M4A/M4V/MOV containers (ID32 box), AIFF/AIFC files (ID3 chunk), and AAC/ADTS streams (prepended ID3v2).

Visit https://mp3tag.js.org to learn more about the library and view it in action through an editor. You can also explore the examples directory.

The website is also open-sourced and can be viewed at the gh-pages branch.

Features

• Read, write, and remove ID3 tags (Supports ID3v1, ID3v2.2, ID3v2.3, and ID3v2.4)
• Read and write ID3v2 tags in MP4/M4A/M4V/MOV containers (via ID32 box)
• Read and write ID3v2 tags in AIFF/AIFC files (via ID3 chunk)
• Read and write ID3v2 tags in AAC/ADTS streams (prepended ID3v2)
• Partial reading from Blob/File without loading entire file into memory
• Supports unsynchronisation
• Standards compliant. See ~~id3.org~~ mutagen-specs.readthedocs.io

Installation

You can download the ready-to-use script at GitHub releases or you can build your own by cloning this repository using git then build it.

git clone https://github.com/eidoriantan/mp3tag.js
cd ./mp3tag.js
npm install
npm run build

You can also install this package by using npm:

npm install --save mp3tag.js@latest

If you are using a browser, you can just install the library through a CDN:

<script src="https://cdn.jsdelivr.net/npm/mp3tag.js@latest/dist/mp3tag.min.js">

Usage

For browsers:

<input type="file" id="input-file" accept="audio/mpeg,audio/mp4,audio/x-m4a,audio/aiff,audio/aac">
<script>
const inputFile = document.getElementById('input-file')
inputFile.addEventListener('change', function () {
  [...this.files].forEach(async (file) => {
    const buffer = await file.arrayBuffer()

    // MP3Tag Usage
    const mp3tag = new MP3Tag(buffer)
    mp3tag.read()

    // Handle error if there's any
    if (mp3tag.error !== '') throw new Error(mp3tag.error)
    else console.log(mp3tag.tags)
  })
})
</script>

<input type="file" id="input-file" accept="audio/mpeg,audio/mp4,audio/x-m4a,audio/aiff,audio/aac">
<script>
inputFile.addEventListener('change', function () {
  const reader = new FileReader()
  reader.onload = function () {
    const buffer = this.result

    // MP3Tag Usage
    const mp3tag = new MP3Tag(buffer)
    mp3tag.read()

    // Handle error if there's any
    if (mp3tag.error !== '') throw new Error(mp3tag.error)
    else console.log(mp3tag.tags)
  }

  if (this.files.length > 0) {
    reader.readAsArrayBuffer(this.files[0])
  }
})
</script>

For Node.js:

const MP3Tag = require('mp3tag.js')
const fs = require('fs')

const buffer = fs.readFileSync('/path/to/audio.mp3')
const mp3tag = new MP3Tag(buffer)

mp3tag.read()

// Handle error if there's any
if (mp3tag.error !== '') throw new Error(mp3tag.error)
else console.log(mp3tag.tags)

import { openAsBlob } from 'node:fs'
import MP3Tag from 'mp3tag.js'

async function main () {
  const blob = await openAsBlob('/path/to/audio.mp3')
  const arrayBuffer = await blob.arrayBuffer()
  const mp3tag = new MP3Tag(arrayBuffer)
  mp3tag.read()

  if (mp3tag.error !== '') throw new Error(mp3tag.error)
  else console.log(mp3tag.tags)
}

main()

Partial reading with readBlob

For read-only scenarios, you can read the metadata without loading the entire file into memory. MP3Tag.readBlob() accepts a Blob (or File) and uses blob.slice() to read only the bytes it needs.

In the browser:

<input type="file" id="input-file" accept="audio/mpeg,audio/mp4,audio/x-m4a,audio/aiff,audio/aac">
<script>
const inputFile = document.getElementById('input-file')
inputFile.addEventListener('change', async function () {
  for (const file of this.files) {
    // Only reads headers + tag data, not the entire file
    const tags = await MP3Tag.readBlob(file)
    console.log(tags.title, tags.artist)
  }
})
</script>

In Node.js (requires Node 19.8+):

import { openAsBlob } from 'node:fs'
import MP3Tag from 'mp3tag.js'

const blob = await openAsBlob('/path/to/large-file.mp3')
const tags = await MP3Tag.readBlob(blob)
console.log(tags.title, tags.artist)

readBlob accepts the same options as read:

const tags = await MP3Tag.readBlob(blob, {
  id3v1: true,
  id3v2: true,
  mp4: true,
  aiff: true,
  aac: true,
  unsupported: false
})

MP4/M4A Support

mp3tag.js supports reading and writing ID3v2 tags embedded in MP4/M4A containers using the ID32 box format. The library automatically detects MP4 files and handles the container structure transparently.

const MP3Tag = require('mp3tag.js')
const fs = require('fs')

// Reading from MP4/M4A
const buffer = fs.readFileSync('/path/to/audio.m4a')
const mp3tag = new MP3Tag(buffer)
mp3tag.read()

if (mp3tag.error !== '') throw new Error(mp3tag.error)
console.log(mp3tag.tags.title)  // Works the same as MP3

// Writing to MP4/M4A
mp3tag.tags.v2.TIT2 = 'New Title'
mp3tag.tags.v2.TPE1 = 'New Artist'
mp3tag.save({
  id3v2: { padding: 0 },
  mp4: { language: 'eng' }  // Optional: ISO-639-2/T language code (default: 'und')
})

if (mp3tag.error !== '') throw new Error(mp3tag.error)
fs.writeFileSync('/path/to/audio.m4a', Buffer.from(mp3tag.buffer))

Note: MP4 support focuses on ID32 boxes containing ID3v2 data. Native iTunes metadata (ilst atoms) is not supported.

AIFF/AIFC Support

mp3tag.js supports reading and writing ID3v2 tags in AIFF and AIFC audio files. Tags are stored in an "ID3 " chunk within the AIFF container structure.

const MP3Tag = require('mp3tag.js')
const fs = require('fs')

// Reading from AIFF
const buffer = fs.readFileSync('/path/to/audio.aiff')
const mp3tag = new MP3Tag(buffer)
mp3tag.read()

if (mp3tag.error !== '') throw new Error(mp3tag.error)
console.log(mp3tag.tags.title)  // Works the same as MP3

// Writing to AIFF
mp3tag.tags.v2.TIT2 = 'New Title'
mp3tag.tags.v2.TPE1 = 'New Artist'
mp3tag.save({ id3v2: { padding: 0 } })  // No padding recommended for AIFF

if (mp3tag.error !== '') throw new Error(mp3tag.error)
fs.writeFileSync('/path/to/audio.aiff', Buffer.from(mp3tag.buffer))

AAC/ADTS Support

mp3tag.js supports reading and writing ID3v2 tags in raw AAC/ADTS audio streams. Tags are prepended to the audio data, similar to MP3 files.

const MP3Tag = require('mp3tag.js')
const fs = require('fs')

// Reading from AAC
const buffer = fs.readFileSync('/path/to/audio.aac')
const mp3tag = new MP3Tag(buffer)
mp3tag.read()

if (mp3tag.error !== '') throw new Error(mp3tag.error)
console.log(mp3tag.tags.title)  // Works the same as MP3

// Writing to AAC
mp3tag.tags.v2.TIT2 = 'New Title'
mp3tag.tags.v2.TPE1 = 'New Artist'
mp3tag.save({ id3v2: { padding: 1024, unsynch: true } })  // Unsync recommended for AAC

if (mp3tag.error !== '') throw new Error(mp3tag.error)
fs.writeFileSync('/path/to/audio.aac', Buffer.from(mp3tag.buffer))

Note: AAC support is for raw ADTS streams (.aac files). For AAC audio in MP4 containers (.m4a files), see the MP4/M4A Support section above.

Read Options

mp3tag.read({
  id3v1: true,       // Read ID3v1 tags (default: true)
  id3v2: true,       // Read ID3v2 tags (default: true)
  mp4: true,         // Detect and read from MP4 containers (default: true)
  aiff: true,        // Detect and read from AIFF containers (default: true)
  aac: true,         // Detect and read from AAC/ADTS streams (default: true)
  unsupported: false // Parse unsupported frames as raw bytes (default: false)
})

Write Options

mp3tag.save({
  strict: false,        // Enable strict validation (default: false)
  id3v1: {
    include: false      // Write ID3v1 tags (default: false)
  },
  id3v2: {
    include: true,      // Write ID3v2 tags (default: true)
    version: 3,         // ID3v2 version: 2, 3, or 4 (default: from source or 3)
    padding: 2048,      // Padding bytes after tags (default: 2048, use 0 for MP4)
    unsynch: false,     // Use unsynchronisation (default: false)
    unsupported: false  // Write unsupported frames (default: false)
  },
  mp4: {
    language: 'und'     // ISO-639-2/T language code for ID32 box (default: 'und')
  }
})

If you want detailed documentation, please visit the documentations page at mp3tag.js.org.

Support

If you had found a bug or any unexpected behavior, you can submit an issue through GitHub issues. If you want to contribute to this repository, please refer to CONTRIBUTING.md.