Web/API/Fetchevent/FetchEvent

The FetchEvent() constructor creates a new FetchEvent object.

Syntax

var fetchEvent = new FetchEvent(type, init);

Parameters

type

A DOMString object specifying which event the object represents. This is always fetch for Fetch events.

init Optional

An object conforming to the FetchEventInit dictionary, containing options to apply to the event object. Options are as follows:

clientId Read only

The Client that the current service worker is controlling.

isReload ' Read only

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.

preloadResponse Read only

A Promise which returns a previously-loaded response to the client.

replacesClientId Read only

A DOMString which identifies the client which is being replaced by resultingClientId.

resultingClientId Read only

A DOMString containing the new clientId if the client changes as a result of the page load.

request Read only

The Request object that would have triggered the event handler.

Specifications

Specification	Status	Comment
Service WorkersThe definition of 'FetchEvent() constructor' in that specification.	Working Draft	Initial definition.

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
FetchEvent() constructor Experimental'	Chrome Full support 40	Edge Full support ≤18	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 No support No	WebView Android Full support 40	Chrome Android Full support 40	Firefox Android Full support 44	Opera Android Full support 27	Safari iOS No support No	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.

See also

• Promise
• Fetch API

FetchEvent() by Mozilla Contributors is licensed under CC-BY-SA 2.5.