AudioWorkletNode

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This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

Although the interface is available outside secure contexts, the BaseAudioContext.audioWorklet property is not, thus custom AudioWorkletProcessors cannot be defined outside them.

The AudioWorkletNode interface of the Web Audio API represents a base class for a user-defined AudioNode, which can be connected to an audio routing graph along with other nodes. It has an associated AudioWorkletProcessor, which does the actual audio processing in a Web Audio rendering thread.

Constructor

AudioWorkletNode()
Creates a new instance of an AudioWorkletNode object.

Properties

Also Inherits properties from its parent, AudioNode.

AudioWorkletNode.port Read only
Returns a MessagePort used for bidirectional communication between the node and its associated AudioWorkletProcessor. The other end is available under the port property of the processor.
AudioWorkletNode.parameters Read only
Returns an AudioParamMap — a collection of AudioParam objects. They are instantiated during the creation of the underlying AudioWorkletProcessor. If the AudioWorkletProcessor has a static parameterDescriptors getter, the AudioParamDescriptor array returned from it is used to create AudioParam objects on the AudioWorkletNode. With this mechanism it is possible to make your own AudioParam objects accessible from your AudioWorkletNode. You can then use their values in the associated AudioWorkletProcessor.

Event handlers

AudioWorkletNode.onprocessorerror
Fired when an error is thrown in associated AudioWorkletProcessor. Once fired, the processor and consequently the node will output silence throughout its lifetime.

Methods

Also inherits methods from its parent, AudioNode.

The AudioWorkletNode interface does not define any methods of its own.

Examples

In this example we create a custom AudioWorkletNode that outputs white noise.

First, we need to define a custom AudioWorkletProcessor, which will output white noise, and register it. Note that this should be done in a separate file.

// white-noise-processor.js
class WhiteNoiseProcessor extends AudioWorkletProcessor {
  process (inputs, outputs, parameters) {
    const output = outputs[0]
    output.forEach(channel => {
      for (let i = 0; i < channel.length; i++) {
        channel[i] = Math.random() * 2 - 1
      }
    })
    return true
  }
}

registerProcessor('white-noise-processor', WhiteNoiseProcessor)

Next, in our main script file we'll load the processor, create an instance of AudioWorkletNode passing it the name of the processor, and connect the node to an audio graph.

const audioContext = new AudioContext()
await audioContext.audioWorklet.addModule('white-noise-processor.js')
const whiteNoiseNode = new AudioWorkletNode(audioContext, 'white-noise-processor')
whiteNoiseNode.connect(audioContext.destination)

Specifications

Specification Status Comment
Web Audio API
The definition of 'AudioWorkletNode' in that specification.
Working Draft

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
AudioWorkletNodeChrome Full support 66Edge ? Firefox ? IE ? Opera Full support YesSafari ? WebView Android Full support 66Chrome Android Full support 66Firefox Android ? Opera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes
AudioWorkletNode() constructorChrome Full support 66Edge ? Firefox ? IE ? Opera ? Safari ? WebView Android Full support 66Chrome Android Full support 66Firefox Android ? Opera Android ? Safari iOS ? Samsung Internet Android ?
onprocessorerrorChrome Full support 66Edge ? Firefox ? IE ? Opera ? Safari ? WebView Android Full support 66Chrome Android Full support 66Firefox Android ? Opera Android ? Safari iOS ? Samsung Internet Android ?
parametersChrome Full support 66Edge ? Firefox ? IE ? Opera Full support YesSafari ? WebView Android Full support 66Chrome Android Full support 66Firefox Android ? Opera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes
portChrome Full support 66Edge ? Firefox ? IE ? Opera Full support YesSafari ? WebView Android Full support 66Chrome Android Full support 66Firefox Android ? Opera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes
processorerror eventChrome Full support 66Edge ? Firefox ? IE ? Opera ? Safari ? WebView Android Full support 66Chrome Android Full support 66Firefox Android ? Opera Android ? Safari iOS ? Samsung Internet Android ?

Legend

Full support  
Full support
Compatibility unknown  
Compatibility unknown

See also