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 aborted read-only property of the FetchSignal interface returns a Boolean that indicates whether the fetch request(s) the signal is communicating with is/are aborted (true) or not (false).


var isAborted = signal.aborted;


A Boolean


In the following snippet, we create a new FetchController object, get its signal, and then give the signal to the fetch request via the signal parameter of its init object so the controller can control it. Later on we specify an event listener on the FetchSignal so that if whether or not it has been aborted, an appropriate log is sent to the console.

var controller = new FetchController();
var signal = controller.signal;

signal.aborted ? console.log('Fetch has been aborted') : console.log('Fetch not aborted');

You can find a work-in-progress demo showing usage of FetchController on GitHub (see the source code and the live example).


Not part of a specification yet.

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support

No support

No support No support[1] No support

No support

No support
Feature Android Android Webview Edge Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile Chrome for Android
Basic support No support No support No support No support[1] No support No support No support No support

[1] Hidden behind a preference in 55+ Nightly. In about:config, you need to create two new boolean prefs — dom.fetchObserver.enabled and dom.fetchController.enabled — and set the values of both to true.

See also

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