The Window.onunhandledrejection property is an event handler for processing unhandledrejection events, which are raised for unhandled Promise rejections.


window.addEventListener("unhandledrejection", function(event) { ... });
window.onunhandledrejection = function(event) { ...};

The event received by the event handler is a PromiseRejectionEvent.


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

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 49 ? ? ? ?
Feature Android Android Webview Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile Chrome for Android
Basic support No support No support ? ? ? ? ? No support


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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.

API Event Handler events Events HTML DOM onunhandledrejection Promises Property Reference WindowEventHandlers