Web/API/ServiceWorkerContainer/message event

The message event is used in a page controlled by a service worker to receive messages from the service worker.

Bubbles	No
Cancelable	No
Interface	MessageEvent
Event handler property	onmessage

Examples

In this example the service worker get the client's ID from a fetch event and then sends it a message using Client.postMessage:

// in the service worker
async function messageClient(clientId) {
    const client = await clients.get(clientId);
    client.postMessage('Hi client!');
}

addEventListener('fetch', (event) => {
    messageClient(event.clientId);
    event.respondWith(() => {
      // ...
    });
});

The client can receive the message by listening to the message event:

// in the page being controlled
navigator.serviceWorker.addEventListener('message', (message) => {
    console.log(message);
});

Specifications

Specification	Status
Service WorkersThe definition of 'message' in that specification.	Working Draft

Browser compatibility

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

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
message event	Chrome Full support 40	Edge Full support 17 Full support 17 Full support 16 Disabled' Disabled' From version 16: this feature is behind the Enable service workers preference.	Firefox Full support 44 Notes' Full support 44 Notes' Notes' Extended Support Releases (ESR) before Firefox 78 ESR do not support service workers and the Push API.	IE No support No	Opera Full support 27	Safari Full support 11.1	WebView Android Full support 40	Chrome Android Full support 40	Firefox Android Full support 44	Opera Android Full support 27	Safari iOS Full support 11.3	Samsung Internet Android Full support 4.0

Legend

Full support  

Full support

No support  

No support

See implementation notes.'

See implementation notes.

User must explicitly enable this feature.'

User must explicitly enable this feature.

See also

• Using Service Workers
• Service workers basic code example
• Is ServiceWorker ready?
• Using web workers

ServiceWorkerContainer: message event by Mozilla Contributors is licensed under CC-BY-SA 2.5.