AbortController.signal

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The signal read-only property of the AbortController interface returns an AbortSignal object instance, which can be used to communicate with/abort a DOM request as desired.

Syntax

var signal = abortController.signal;

Value

An AbortSignal object instance.

Examples

In the following snippet, we aim to download a video using the Fetch API.

We first create a controller using the AbortController() constructor, then grab a reference to its associated AbortSignal object using the AbortController.signal property.

When the fetch request is initiated, we pass in the AbortSignal as an option inside the request's options object (see {signal}, below). This associates the signal and controller with the fetch request and allows us to abort it by calling AbortController.abort(), as seen below in the second event listener.

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

var downloadBtn = document.querySelector('.download');
var abortBtn = document.querySelector('.abort');

downloadBtn.addEventListener('click', fetchVideo);

abortBtn.addEventListener('click', function() {
  controller.abort();
  console.log('Download aborted');
});

function fetchVideo() {
  ...
  fetch(url, {signal}).then(function(response) {
    ...
  }).catch(function(e) {
    reports.textContent = 'Download error: ' + e.message;
  })
}

Note: When abort() is called, the fetch() promise rejects with an AbortError.

You can find a full working example on GitHub — see abort-api (see it running live also).

Specifications

Specification Status Comment
DOM
The definition of 'signal' in that specification.
Living Standard Initial definition

Browser compatibility

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
signal
Experimental
Chrome Full support 66Edge Full support 16Firefox Full support 57IE No support NoOpera Full support 53Safari Full support 12.1
Full support 12.1
Partial support 11.1
Notes
Notes Even though window.AbortController is defined, it doesn't really abort fetch requests. See bug 174980.
WebView Android Full support 66Chrome Android Full support 66Firefox Android Full support 57Opera Android Full support 47Safari iOS Full support 12.2
Full support 12.2
Partial support 11.3
Notes
Notes Even though window.AbortController is defined, it doesn't really abort fetch requests. See bug 174980.
Samsung Internet Android Full support 9.0

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