files/en-us/web/api/audiocontext/suspend/index.md
{{ APIRef("Web Audio API") }}
The suspend() method of the {{ domxref("AudioContext") }} Interface suspends the progression of time in the audio context, temporarily halting audio hardware access and reducing CPU/battery usage in the process — this is useful if you want an application to power down the audio hardware when it will not be using an audio context for a while.
This method will cause an INVALID_STATE_ERR exception to be thrown if called on an {{domxref("OfflineAudioContext")}}.
suspend()
None.
A {{jsxref("Promise")}} that resolves with {{jsxref('undefined')}}. The promise is rejected if the context has already been closed.
The following snippet is taken from our AudioContext states demo (see it running live.) When the suspend/resume button is clicked, the {{domxref("BaseAudioContext/state", "AudioContext.state")}} is queried — if it is running, suspend() is called; if it is suspended, {{domxref("AudioContext/resume", "resume()")}} is called. In each case, the text label of the button is updated as appropriate once the promise resolves.
susResBtn.onclick = () => {
if (audioCtx.state === "running") {
audioCtx.suspend().then(() => {
susResBtn.textContent = "Resume context";
});
} else if (audioCtx.state === "suspended") {
audioCtx.resume().then(() => {
susResBtn.textContent = "Suspend context";
});
}
};
{{Specifications}}
{{Compat}}