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.)


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


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


Service Workers 1
# dom-serviceworkerglobalscope-onmessage

Browser compatibility

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