MessageEvent: ports property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2015.

Note: This feature is available in Web Workers.

The ports read-only property of the MessageEvent interface is an array of MessagePort objects containing all MessagePort objects sent with the message, in order.

Value

An array of MessagePort objects.

Examples

js
onconnect = (e) => {
  const port = e.ports[0];

  port.addEventListener("message", (e) => {
    const workerResult = `Result: ${e.data[0] * e.data[1]}`;
    port.postMessage(workerResult);
  });

  port.start(); // Required when using addEventListener. Otherwise called implicitly by onmessage setter.
};

Specifications

Specification
HTML Standard
# dom-messageevent-ports-dev

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
ports

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support

See also

  • ExtendableMessageEvent — similar to this interface but used in interfaces that needs to give more flexibility to authors.