Web/API/AudioWorkletNode/port

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

The read-only port property of the AudioWorkletNode interface returns the associated MessagePort. It can be used to communicate between the node and its associated AudioWorkletProcessor.

Note: The port at the other end of the channel is available under the port property of the processor.

Syntax

audioWorkletNodeInstance.port;

Value

The MessagePort object that is connecting the AudioWorkletNode and its associated AudioWorkletProcessor.

Examples

To demonstrate bidirectional communication capabilities, we'll create an AudioWorkletProcessor, which will output silence and respond to ping requests from its AudioWorkletNode.

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

// ping-pong-processor.js
class PingPongProcessor extends AudioWorkletProcessor {
  constructor (...args) {
    super(...args)
    this.port.onmessage = (e) => {
      console.log(e.data)
      this.port.postMessage('pong')
    }
  }
  process (inputs, outputs, parameters) {
    return true
  }
}

registerProcessor('ping-pong-processor', PingPongProcessor)

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

const audioContext = new AudioContext()
await audioContext.audioWorklet.addModule('ping-pong-processor.js')
const pingPongNode = new AudioWorkletNode(audioContext, 'ping-pong-processor')
// send the message containing 'ping' string
// to the AudioWorkletProcessor from the AudioWorkletNode every second
setInterval(() => pingPongNode.port.postMessage('ping'), 1000)
pingPongNode.port.onmessage = (e) => console.log(e.data)
pingPongNode.connect(audioContext.destination)

This will output "ping" and "pong" strings to the console every second.

Specifications

Specification	Status	Comment
Web Audio APIThe definition of 'port' in that specification.	Working Draft

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`port`	Chrome Full support 67	Edge Full support 79	Firefox Full support 76	IE No support No	Opera Full support Yes	Safari No support No	WebView Android Full support 67	Chrome Android Full support 67	Firefox Android Full support 79	Opera Android Full support Yes	Safari iOS No support No	Samsung Internet Android Full support 9.0

Legend

Full support: Full support
No support: No support