The registerProcessor method of the AudioWorkletGlobalScope interface registers a class constructor derived from AudioWorkletProcessor interface under a specified name.


AudioWorkletGlobalScope.registerProcessor(name, processorCtor);


A string representing the name under which the processor will be registered.
The constructor of a class derived from AudioWorkletProcessor.

Note: A key-value pair { name: constructor } is saved internally in the AudioWorkletGlobalScope once  the processor is registered. The name is to be referred to when creating an AudioWorkletNode based on the registered processor. A new processor by the given name is internally created and associated with the new node.

Return value



  • The name is an empty string, or
  • a constructor under the given name is already registered. Registering the same name twice is not allowed.


In this example we create a custom AudioWorkletNode that outputs silence.

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

// test-processor.js
class TestProcessor extends AudioWorkletProcessor {
  process (inputs, outputs, parameters) {
    return true

registerProcessor('test-processor', TestProcessor)

Next, in our main script file we'll load the processor, create an instance of AudioWorkletNode — passing it the processor name that we used when calling registerProcessor — and connect it to an audio graph.

const audioContext = new AudioContext()
await audioContext.audioWorklet.addModule('test-processor.js')
const node = new AudioWorkletNode(audioContext, 'test-processor')


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

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
registerProcessorChrome Full support 66Edge Full support 79Firefox Full support 76IE No support NoOpera Full support 53Safari No support NoWebView Android Full support 66Chrome Android Full support 66Firefox Android No support NoOpera Android Full support 47Safari iOS No support NoSamsung Internet Android Full support 9.0


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See also