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Awesome Open Source


WebAudioFont is a set of resources and associated technology that uses sample-based synthesis to play musical instruments in the browser. You can choose from thousands of instrument, see Catalog.


see Contact me if you need different license.

Code examples

Example applications

Use cases

  • Virtual instruments
  • Interactive music generated on the fly
  • Sound effects for non-music applications


How to use

Add a link to WebAudioFontPlayer.js and the instrument file. Invoke queueWaveTable.

Hello, world

Minimal HTML page

		<script src=''></script>
		<script src=''></script>
			var AudioContextFunc = window.AudioContext || window.webkitAudioContext;
			var audioContext = new AudioContextFunc();
			var player=new WebAudioFontPlayer();
			player.loader.decodeAfterLoading(audioContext, '_tone_0250_SoundBlasterOld_sf2');
			function play(){
				player.queueWaveTable(audioContext, audioContext.destination
					, _tone_0250_SoundBlasterOld_sf2, 0, 12*4+7, 2);
				return false;
		<p><a href='javascript:play();'>Hello, world!</a></p>

See live example.

Use queueWaveTable to play single note. Use queueChord, queueSnap, queueStrumDown, queueStrumUp to play chords. See live example for strumming.

Use time for notes to define sequence. See live example of sequencer.

Dynamic loading

Use the startLoad and waitLoad functions.

var instr=null;
var AudioContextFunc = window.AudioContext || window.webkitAudioContext;
var audioContext = new AudioContextFunc();
var player=new WebAudioFontPlayer();
function changeInstrument(path,name){
	player.loader.startLoad(audioContext, path, name);
	player.loader.waitLoad(function () {

All loaded instruments are cached in memory.

See live example

Effects and mixer

Use WebAudioFontChannel to create a chain of 10-band equalizers. Use WebAudioFontReverberator to add echo.

See live example

Custom samples

See tutorial


WebAudioFont doesn't require installation. It hosts all code and instruments at GitHub Pages.

Minimal NPM code (if you need this)


var webaudiofont = require('webaudiofont');
var player = new WebAudioFontPlayer();


"devDependencies": {

Parts of WebAudioFont

WebAudioFont uses Web Audio API to play instruments. Synthesizer uses wavetables to play sound. Instruments came from free soundfonts:

How to use catalog of sounds:

  • open index page
  • find an instrument
  • copy the name of the file to include the instrument data
  • copy the name of the variable to refer to the instrument
  • add this info to a page

Use drumInfo and instrumentInfo in realtime. See live example.


WebAudioFontPlayer has the function queueWaveTable(audioContext, target, preset, when, pitch, duration, volume, slides)


  • audioContext - AudioContext
  • target - a node to connect to, for example audioContext.destination
  • preset - variable with the instrument preset
  • when - when to play, audioContext.currentTime or 0 to play now, audioContext.currentTime + 3 to play after 3 seconds
  • pitch - note pitch from 0 to 127, for example 2+12*4 to play D of fourth octave (use MIDI key for drums)
  • duration - note duration in seconds, for example 4 to play 4 seconds
  • volume - 0.0 <=1.0 volume (0 is 'no value', 'no value' is 1)
  • slides - array of pitch bends

The function queueWaveTable returns an envelope object. You can use this object to cancel a sound or to access AudioBufferSourceNode.


Use queueChord, queueStrumUp, queueStrumDown, queueSnap for chords. See live example.

How to get help

Feel free to ask for any kind of help at project issues.


See ReactJS implementation.


See TypeScript implementation.

Catalog of instruments

The catalog consists of a full set of MIDI standards. Each instrument has 5-10 sound variations from different soundfonts.

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javascript (70,283
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player (248
music-player (177
midi (147
sound (123
synthesizer (62
synth (28
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