jsfxr Documentation

Depending on your module system, import the sfxr object as follows:

ES Modules / Bundlers:

import { sfxr } from "jsfxr";

CommonJS:

const sfxr = require("jsfxr").sfxr;

To use jsfxr directly in a web page without a module bundler, include the following scripts. This will expose the sfxr namespace globally:

<script src="https://sfxr.me/riffwave.js"></script>
<script src="https://sfxr.me/sfxr.js"></script>

To use jsfxr in a Node.js environment or with a modern bundler, install it using npm:

npm i jsfxr

The jsfxr library requires RIFFWAVE to be available in the global scope (globalThis or window) before the main sfxr.js logic is loaded. If you are using the ESM wrapper sfxr.mjs, this initialization is handled automatically. However, if you are manually integrating the components, you must ensure RIFFWAVE is attached to the global object before calling SoundEffect.generate().

import RIFFWAVE from './riffwave.js';

// Ensure RIFFWAVE is global before loading sfxr
if (typeof globalThis !== 'undefined') globalThis.RIFFWAVE = RIFFWAVE;
if (typeof window !== 'undefined') window.RIFFWAVE = RIFFWAVE;

import jsfxr from './sfxr.js';

You can convert between the full JSON sound definition and the compressed Base58 string format using sfxr.b58encode and sfxr.b58decode.

var b58string = sfxr.b58encode(sound);
var sound = sfxr.b58decode(b58string);

You can quickly generate sound effects using built-in preset algorithms. Use sfxr.generate(preset) to create the sound object and sfxr.play(sound) to play it immediately via the Web Audio API.

Available presets: pickupCoin, laserShoot, explosion, powerUp, hitHurt, jump, blipSelect, synth, tone, click, and random.

import { sfxr } from "jsfxr";

const preset = "pickupCoin";
const sound = sfxr.generate(preset);

sfxr.play(sound);

You can use the sfxr.me web application to design sounds, click the "serialize" button, and copy the resulting JSON. Use sfxr.toAudio(sound) to convert this JSON object into an audio object that you can play.

var sound = {
  "oldParams": true,
  "wave_type": 1,
  // ... other parameters
  "sample_rate": 44100,
  "sample_size": 8
};

var a = sfxr.toAudio(sound);
a.play();

To save space, you can use the short URL compressed version of a sound. Pass the Base58 string directly to sfxr.toAudio() to create a playable audio object.

var a = sfxr.toAudio("5EoyNVSymuxD8s7HP1ixqdaCn5uVGEgwQ3kJBR7bSoApFQzm7E4zZPW2EcXm3jmNdTtTPeDuvwjY8z4exqaXz3NGBHRKBx3igYfBBMRBxDALhBSvzkF6VE2Pv");
a.play();

Use the following methods to extract raw audio data from a sound object:

• sfxr.toBuffer(sound): Returns an array of samples. By default, the buffer contains audio rendered at a sample rate of 44100.
• sfxr.toWave(sound): Returns an object containing a dataURI for a WAV file of the sound.

// Get audio buffer
var buffer = sfxr.toBuffer(sound);

// Get WAV DataURI
var a = sfxr.toWave(sound);
console.log(a.dataURI);

The sfxr.play(synthdef) method is a high-level helper that converts a sound definition into audio and plays it immediately.

In a browser environment, it uses the Web Audio API if available, otherwise it falls back to an HTML5 Audio object using a Data URI. It returns an object containing a play method and a setVolume method for controlling the playback.

// synthdef can be a Params object or a B58 encoded string
sfxr.play(mySynthDef);

Use sfxr.generate(algorithm, options) to quickly create a sound effect using one of the built-in preset algorithms. The algorithm string must correspond to a method name on the Params prototype (e.g., 'pickupCoin', 'explosion', 'laserShoot').

Options:

• sound_vol: Volume (default: 0.25)
• sample_rate: Sample rate in Hz (default: 44100)
• sample_size: Bit depth (default: 8)

Returns a SoundEffect instance configured with the randomized preset.

// Generate a random explosion sound
const explosion = sfxr.generate('explosion', { sound_vol: 0.5 });

// Play it immediately (if in a browser environment)
sfxr.play(explosion);