This feature has been removed from the Web standards. Though some browsers may still support it, it is in the process of being dropped. Avoid using it and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

The CustomEvent.initCustomEvent() method initializes a CustomEvent object. If the event has already been dispatched, this method does nothing.

Events initialized in this way must have been created with the Document.createEvent() method. This method must be called to set the event before it is dispatched, using EventTarget.dispatchEvent(). Once dispatched, it doesn't do anything anymore.

Do not use this method anymore, as it is deprecated.

Instead use specific event constructors, like CustomEvent(). The page on Creating and triggering events gives more information about the way to use these.


event.initCustomEvent(type, canBubble, cancelable, detail);


Is a DOMString containing the name of the event.
Is a Boolean indicating whether the event bubbles up through the DOM or not.
Is a Boolean indicating whether the event is cancelable.
The data passed when initializing the event.


Specification Status Comment
The definition of 'CustomEvent' in that specification.
Living Standard Initial definition, but already deprecated in favor of the use of a constructor, CustomEvent()

Browser compatibility

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support (Yes)[1] (Yes) 6 (6) 9 11 5.1 (533.3)
Feature Android Webview Chrome for Android Edge Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile
Basic support (Yes)[1] (Yes)[1] (Yes) 6.0 (6) ? ? ?

[1] Starting in Chrome 59, canBubble, cancelable, and detail are optional parameters defaulting to false, false, and null respectively.

See also

Document Tags and Contributors

 Contributors to this page: molsson, jpmedley, erikadoyle, Jeremie, Sole, fscholz, teoli
 Last updated by: molsson,