The ExtendableEvent() constructor creates a new ExtendableEvent object.


var extendableEvent = new ExtendableEvent(type, init);


The type of the ExtendableEvent, for example install, activate.
init Optional
An options object containing any custom settings that you want to apply to the event object. Currently no possible options exist inside the spec, but this has been defined for forward compatibility across the different derived events.


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

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
ExtendableEvent() constructor
Chrome Full support 40Edge Full support 17Firefox Full support 44
Full support 44
Notes Extended Support Releases (ESR) before Firefox 78 ESR do not support service workers and the Push API.
IE No support NoOpera Full support 24Safari No support NoWebView Android Full support 40Chrome Android Full support 40Firefox Android Full support 44Opera Android Full support 24Safari iOS No support NoSamsung Internet Android Full support 4.0


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.

See also