ServiceWorkerGlobalScope.onmessage

The onmessage property of the ServiceWorkerGlobalScope interface is an event handler fired whenever a message event occurs — when incoming messages are received.

Note: Service workers define the extendable event to allow extending the lifetime of the event. For the message event, service workers use the ExtendableMessageEvent interface which extends the ExtendableEvent interface.

Note: Messages received from service worker contexts (e.g. as the event object of onmessage) are represented by MessageEvent objects in modern browsers, for consistency with other web messaging features. (They used to be represented by ServiceWorkerMessageEvent objects, which have now been deprecated.)

Syntax

serviceWorkerGlobalScope.onmessage = function(extendableMessageEvent) { ... };

Example

self.addEventListener('message', function(messageEvent) {
  console.log('Handling message event:', messageEvent);
})

Specifications

Specification	Status	Comment
Service Workers The definition of 'Event Handlers' in that specification.	Working Draft	Initial definition

Browser compatibility

	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
`onmessage` Experimental	Chrome Full support 40	Edge Full support ≤79	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 24	Safari Full support 11.1	WebView Android Full support 40	Chrome Android Full support 40	Firefox Android Full support 44	Opera Android Full support 24	Safari iOS Full support 11.3	Samsung Internet Android Full support 4.0

Legend

Full support: Full support
No support: No support
Experimental. Expect behavior to change in the future.: Experimental. Expect behavior to change in the future.
See implementation notes.: See implementation notes.