id3.js is a JavaScript library for reading and parsing ID3 tags of MP3 files. id3.js can parse both ID3v1 and ID3v2 tags within a browser or Node environment. It also supports reading from local files (Node-only), same-origin URLs (AJAX) and File instances (HTML5 File API).

<script src="id3.min.js"></script>
<script type="text/javascript">
id3('/audio/track.mp3', function(err, tags) {
	// tags now contains v1, v2 and merged tags
});
</script>

Here the MP3 is being requested by partial AJAX requests, such that only the ID3v1 and ID3v2 tags are read rather than the file as a whole.

First, install id3.js using NPM, the Node package manager.

npm install id3js

Then use it like so:

var id3 = require('id3js');

id3({ file: './track.mp3', type: id3.OPEN_LOCAL }, function(err, tags) {
	// tags now contains your ID3 tags
});

Note that here, the type is set to 'local' directly so that id3.js will attempt to read from the local file-system using fs.

This will only work under NodeJS.

<script src="id3.min.js"></script>
<script type="text/javascript">
document.querySelector('input[type="file"]').onchange = function(e) {
	id3(this.files[0], function(err, tags) {
		// tags now contains your ID3 tags
	});
}
</script>

This will read the data from the File instance using slices, so the entire file is not loaded into memory but rather only the tags.

Tags are passed as an object of the following format:

{
	"artist": "Song artist",
	"title": "Song name",
	"album": "Song album",
	"year": "2013",
	"v1": {
		"title": "ID3v1 title",
		"artist": "ID3v1 artist",
		"album": "ID3v1 album",
		"year": "ID3v1 year",
		"comment": "ID3v1 comment",
		"track": "ID3v1 track (e.g. 02)",
		"version": 1.0
	},
	"v2": {
		"artist": "ID3v2 artist",
		"album": "ID3v2 album",
		"version": [4, 0]
	}
}

The artist, title, album and year properties will always exist, though they will default to null. These particular fields are filled by both ID3v1 and ID3v2, the latter taking the priority.

The v2 object will contain a variable number of fields, depending on what is defined in the file, whereas the v1 object will always have the same fields (some of which may be null).

On occasion, an MP3 may have an image embedded in the ID3v2 tag. If this is the case, it will be available through v2.image. This has a structure like so:

{
	"type": "cover-front",
	"mime": "image/jpeg",
	"description": null,
	"data": ArrayBuffer
}

As you can see, the data is provided as an ArrayBuffer. To access it, you may use a DataView or typed array such as Uint8Array.

MIT