AudioContext

Baseline Widely available *

This feature is well established and works across many devices and browser versions. It’s been available across browsers since April 2021.

* Some parts of this feature may have varying levels of support.

The AudioContext interface represents an audio-processing graph built from audio modules linked together, each represented by an AudioNode.

An audio context controls both the creation of the nodes it contains and the execution of the audio processing, or decoding. You need to create an AudioContext before you do anything else, as everything happens inside a context. It's recommended to create one AudioContext and reuse it instead of initializing a new one each time, and it's OK to use a single AudioContext for several different audio sources and pipeline concurrently.

EventTarget BaseAudioContext AudioContext

Constructor

AudioContext()

Creates and returns a new AudioContext object.

Instance properties

Also inherits properties from its parent interface, BaseAudioContext.

AudioContext.baseLatency Read only

Returns the number of seconds of processing latency incurred by the AudioContext passing the audio from the AudioDestinationNode to the audio subsystem.

AudioContext.outputLatency Read only

Returns an estimation of the output latency of the current audio context.

AudioContext.sinkId Read only Experimental Secure context

Returns the sink ID of the current output audio device.

Instance methods

Also inherits methods from its parent interface, BaseAudioContext.

AudioContext.close()

Closes the audio context, releasing any system audio resources that it uses.

AudioContext.createMediaElementSource()

Creates a MediaElementAudioSourceNode associated with an HTMLMediaElement. This can be used to play and manipulate audio from <video> or <audio> elements.

AudioContext.createMediaStreamSource()

Creates a MediaStreamAudioSourceNode associated with a MediaStream representing an audio stream which may come from the local computer microphone or other sources.

AudioContext.createMediaStreamDestination()

Creates a MediaStreamAudioDestinationNode associated with a MediaStream representing an audio stream which may be stored in a local file or sent to another computer.

AudioContext.createMediaStreamTrackSource()

Creates a MediaStreamTrackAudioSourceNode associated with a MediaStream representing an media stream track.

AudioContext.getOutputTimestamp()

Returns a new AudioTimestamp object containing two audio timestamp values relating to the current audio context.

AudioContext.resume()

Resumes the progression of time in an audio context that has previously been suspended/paused.

AudioContext.setSinkId() Experimental Secure context

Sets the output audio device for the AudioContext.

AudioContext.suspend()

Suspends the progression of time in the audio context, temporarily halting audio hardware access and reducing CPU/battery usage in the process.

Events

sinkchange Experimental

Fired when the output audio device (and therefore, the AudioContext.sinkId) has changed.

Examples

Basic audio context declaration:

js
const audioCtx = new AudioContext();

const oscillatorNode = audioCtx.createOscillator();
const gainNode = audioCtx.createGain();
const finish = audioCtx.destination;
// etc.

Specifications

Specification
Web Audio API
# AudioContext

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
AudioContext
AudioContext() constructor
options.latencyHint parameter
options.sampleRate parameter
options.sinkId parameter
Experimental
baseLatency
close
createMediaElementSource
createMediaStreamDestination
createMediaStreamSource
createMediaStreamTrackSource
error event
Experimental
getOutputTimestamp
outputLatency
resume
setSinkId
Experimental
sinkId
Experimental
sinkchange event
Experimental
suspend

Legend

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Full support
Full support
No support
No support
Experimental. Expect behavior to change in the future.
See implementation notes.
Requires a vendor prefix or different name for use.
Has more compatibility info.

See also