CustomEvent: initCustomEvent() method

Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. 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.

Note: This feature is available in Web Workers.

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.

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

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)



A string containing the name of the event.


A boolean value indicating whether the event bubbles up through the DOM or not.


A boolean value indicating whether the event is cancelable.


Any data that will be available to the handler through the CustomEvent.detail property.


DOM Standard
# dom-customevent-initcustomevent

Browser compatibility

BCD tables only load in the browser

See also