This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The FetchEvent() constructor creates a new FetchEvent object.


var myFetchEvent = new FetchEvent(type, init);


The type of the Event.
init Optional
An options object containing any custom settings that you want to apply to the event object. Options are as follows:
  • request: The Request object that would have triggered the event handler.
  • clientId: The Client that the current service worker is controlling. This property is not yet implemented in Chrome.
  • isReload: A Boolean that signifies whether the page was reloaded or not when the event was dispatched. true if yes, and false if not. Typically, pressing the refresh button in a browser is a reload, while clicking a link and pressing the back button is not. If not present, it defaults to false.


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

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 49.0 44.0 (44.0)[1] No support 24 No support
Feature Android Android Webview Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile Chrome for Android
Basic support No support 49.0 44.0 (44.0) (Yes) No support ? No support 49.0

[1] Service workers (and Push) have been disabled in the Firefox 45 Extended Support Release (ESR.)

See also

Document Tags and Contributors

 Contributors to this page: chrisdavidmills, dgashmdn, jpmedley, teoli, kscarfone
 Last updated by: chrisdavidmills,