AudioBufferSourceNode: loop property

The loop property of the AudioBufferSourceNode interface is a Boolean indicating if the audio asset must be replayed when the end of the AudioBuffer is reached.

The loop property's default value is false.


A Boolean which is true if looping is enabled; otherwise, the value is false.

When looping is enabled, the sound begins playing at the time specified as the start point when start() is called. When the time specified by the loopEnd property is reached, playback continues at the time specified by loopStart


Setting loop

In this example, when the user presses "Play", we load an audio track, decode it, and put it into an AudioBufferSourceNode.

The example then sets the loop property to true, so the track loops, and plays the track.

The user can set the loopStart and loopEnd properties using range controls.

let audioCtx;
let buffer;
let source;

const play = document.getElementById("play");
const stop = document.getElementById("stop");

const loopstartControl = document.getElementById("loopstart-control");
const loopstartValue = document.getElementById("loopstart-value");

const loopendControl = document.getElementById("loopend-control");
const loopendValue = document.getElementById("loopend-value");

async function loadAudio() {
  try {
    // Load an audio file
    const response = await fetch("rnb-lofi-melody-loop.wav");
    // Decode it
    buffer = await audioCtx.decodeAudioData(await response.arrayBuffer());
    const max = Math.floor(buffer.duration);
    loopstartControl.setAttribute("max", max);
    loopendControl.setAttribute("max", max);
  } catch (err) {
    console.error(`Unable to fetch the audio file. Error: ${err.message}`);

play.addEventListener("click", async () => {
  if (!audioCtx) {
    audioCtx = new AudioContext();
    await loadAudio();
  source = audioCtx.createBufferSource();
  source.buffer = buffer;
  source.loop = true;
  source.loopStart = loopstartControl.value;
  source.loopEnd = loopendControl.value;
  play.disabled = true;
  stop.disabled = false;
  loopstartControl.disabled = false;
  loopendControl.disabled = false;

stop.addEventListener("click", () => {
  play.disabled = false;
  stop.disabled = true;
  loopstartControl.disabled = true;
  loopendControl.disabled = true;

loopstartControl.addEventListener("input", () => {
  source.loopStart = loopstartControl.value;
  loopstartValue.textContent = loopstartControl.value;

loopendControl.addEventListener("input", () => {
  source.loopEnd = loopendControl.value;
  loopendValue.textContent = loopendControl.value;


Web Audio API
# dom-audiobuffersourcenode-loop

Browser compatibility

BCD tables only load in the browser

See also