Event

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

Note: This feature is available in Web Workers.

The Event interface represents an event which takes place on an EventTarget.

An event can be triggered by the user action e.g. clicking the mouse button or tapping keyboard, or generated by APIs to represent the progress of an asynchronous task. It can also be triggered programmatically, such as by calling the HTMLElement.click() method of an element, or by defining the event, then sending it to a specified target using EventTarget.dispatchEvent().

There are many types of events, some of which use other interfaces based on the main Event interface. Event itself contains the properties and methods which are common to all events.

Many DOM elements can be set up to accept (or "listen" for) these events, and execute code in response to process (or "handle") them. Event-handlers are usually connected (or "attached") to various HTML elements (such as <button>, <div>, <span>, etc.) using EventTarget.addEventListener(), and this generally replaces using the old HTML event handler attributes. Further, when properly added, such handlers can also be disconnected if needed using removeEventListener().

Note: One element can have several such handlers, even for the exact same event—particularly if separate, independent code modules attach them, each for its own independent purposes. (For example, a webpage with an advertising-module and statistics-module both monitoring video-watching.)

When there are many nested elements, each with its own handler(s), event processing can become very complicated—especially where a parent element receives the very same event as its child elements because "spatially" they overlap so the event technically occurs in both, and the processing order of such events depends on the Event bubbling settings of each handler triggered.

Interfaces based on Event

Constructor

Event()

Creates an Event object, returning it to the caller.

Instance properties

Event.bubbles Read only

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

Event.cancelable Read only

A boolean value indicating whether the event is cancelable.

Event.composed Read only

A boolean indicating whether or not the event can bubble across the boundary between the shadow DOM and the regular DOM.

Event.currentTarget Read only

A reference to the currently registered target for the event. This is the object to which the event is currently slated to be sent. It's possible this has been changed along the way through retargeting.

Event.defaultPrevented Read only

Indicates whether or not the call to event.preventDefault() canceled the event.

Event.eventPhase Read only

Indicates which phase of the event flow is being processed. It is one of the following numbers: NONE, CAPTURING_PHASE, AT_TARGET, BUBBLING_PHASE.

Event.isTrusted Read only

Indicates whether or not the event was initiated by the browser (after a user click, for instance) or by a script (using an event creation method, for example).

Event.srcElement Read only Deprecated

An alias for the Event.target property. Use Event.target instead.

Event.target Read only

A reference to the object to which the event was originally dispatched.

Event.timeStamp Read only

The time at which the event was created (in milliseconds). By specification, this value is time since epoch—but in reality, browsers' definitions vary. In addition, work is underway to change this to be a DOMHighResTimeStamp instead.

Event.type Read only

The name identifying the type of the event.

Legacy and non-standard properties

Event.cancelBubble Deprecated

A historical alias to Event.stopPropagation() that should be used instead. Setting its value to true before returning from an event handler prevents propagation of the event.

Event.explicitOriginalTarget Non-standard Read only

The explicit original target of the event.

Event.originalTarget Non-standard Read only

The original target of the event, before any retargetings.

Event.returnValue Deprecated

A historical property still supported in order to ensure existing sites continue to work. Use Event.preventDefault() and Event.defaultPrevented instead.

Event.scoped Read only Deprecated

A boolean value indicating whether the given event will bubble across through the shadow root into the standard DOM. Use composed instead.

Instance methods

Event.composedPath()

Returns the event's path (an array of objects on which listeners will be invoked). This does not include nodes in shadow trees if the shadow root was created with its ShadowRoot.mode closed.

Event.preventDefault()

Cancels the event (if it is cancelable).

Event.stopImmediatePropagation()

For this particular event, prevent all other listeners from being called. This includes listeners attached to the same element as well as those attached to elements that will be traversed later (during the capture phase, for instance).

Event.stopPropagation()

Stops the propagation of events further along in the DOM.

Deprecated methods

Event.initEvent() Deprecated

Initializes the value of an Event created. If the event has already been dispatched, this method does nothing. Use the constructor (Event() instead).

Specifications

Specification
DOM
# interface-event

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
Event
Event() constructor
bubbles
cancelBubble
Deprecated
cancelable
composed
composedPath
currentTarget
defaultPrevented
eventPhase
explicitOriginalTarget
Non-standard
initEvent
Deprecated
isTrusted
originalTarget
Non-standard
preventDefault
returnValue
Deprecated
srcElement
Deprecated
stopImmediatePropagation
stopPropagation
target
timeStamp
type

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
Partial support
Partial support
No support
No support
Non-standard. Check cross-browser support before using.
Deprecated. Not for use in new websites.
See implementation notes.
Uses a non-standard name.
Has more compatibility info.

See also