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.

Note: Rather than using the feature, instead use specific event constructors, like CustomEvent(). The page on Creating and triggering events gives more information about the way to use those.


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

BCD tables only load in the browser

See also