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 handler 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
HTML Standard (HTML)
# unhandled-promise-rejections

Browser compatibility

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See also