Window: rejectionhandled event

The rejectionhandled event is sent to the script's global scope (usually window but also Worker) whenever a JavaScript Promise is rejected but after the promise rejection has been handled. This can be used in debugging and for general application resiliency, in tandem with the unhandledrejection event, which is sent when a promise is rejected but there is no hander for the rejection.

Bubbles No
Cancelable No
Interface PromiseRejectionEvent
Event handler property onrejectionhandled

Example

You can use the rejectionhandled event to log promises that get rejected to the console, along with the reasons why they were rejected:

window.addEventListener("rejectionhandled", event => {
  console.log("Promise rejected; reason: " + event.reason);
}, false);

Specifications

Specification Status Comment
HTML Living Standard
The definition of 'rejectionhandled' in that specification.
Living Standard Initial definition.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
rejectionhandled eventChrome Full support 49Edge Full support ‚ȧ79Firefox Full support 69
Full support 69
Full support 68
Disabled
Disabled From version 68: this feature is behind the dom.promise_rejection_events.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 36Safari Full support 11WebView Android Full support 49Chrome Android Full support 49Firefox Android Full support 68
Disabled
Full support 68
Disabled
Disabled From version 68: this feature is behind the dom.promise_rejection_events.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 36Safari iOS Full support 11.3Samsung Internet Android Full support 5.0

Legend

Full support  
Full support
No support  
No support
User must explicitly enable this feature.
User must explicitly enable this feature.

See also