MessageEvent.ports

The ports read-only property of the MessageEvent interface is an array of MessagePort objects representing the ports associated with the channel the message is being sent through (where appropriate, e.g. in channel messaging or when sending a message to a shared worker).

Syntax

var myPorts = messageEvent.ports;

Value

An array of MessagePort objects.

Example

onconnect = function(e) {
  var port = e.ports[0];

  port.addEventListener('message', function(e) {
    var 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 Status Comment
HTML Living Standard
The definition of 'ports' in that specification.
Living Standard Initial definition

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
portsChrome Full support 1Edge Full support 12Firefox Full support 4IE Full support 9Opera Full support YesSafari Full support 10WebView Android Full support YesChrome Android Full support YesFirefox Android Full support YesOpera Android Full support YesSafari iOS Full support 3Samsung Internet Android Full support Yes

Legend

Full support  
Full support

See also

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

Document Tags and Contributors

Contributors to this page: mdnwebdocs-bot, fscholz, jpmedley, chrisdavidmills
Last updated by: mdnwebdocs-bot,