The MouseEvent interface represents events that occur due to the user interacting with a pointing device (such as a mouse). Common events using this interface include click, dblclick, mouseup, mousedown.

MouseEvent derives from UIEvent, which in turn derives from Event. Though the MouseEvent.initMouseEvent() method is kept for backward compatibility, creating of a MouseEvent object should be done using the MouseEvent() constructor.

Several more specific events derivate from MouseEvent: WheelEvent and DragEvent.

Constructor

MouseEvent()
Creates a MouseEvent object.

Properties

This interface also inherits properties of its parents, UIEvent and Event.

MouseEvent.altKey Read only
Returns true if the alt key was down when the mouse event was fired.
MouseEvent.button Read only
The button number that was pressed when the mouse event was fired. 
MouseEvent.buttons Read only

The buttons being pressed when the mouse event was fired

MouseEvent.clientX Read only
The X coordinate of the mouse pointer in local (DOM content) coordinates.
MouseEvent.clientY Read only
The Y coordinate of the mouse pointer in local (DOM content) coordinates.
MouseEvent.ctrlKey Read only
Returns true if the control key was down when the mouse event was fired.
MouseEvent.metaKey Read only
Returns true if the meta key was down when the mouse event was fired.
MouseEvent.movementX Read only
The X coordinate of the mouse pointer relative to the position of the last mousemove event.
MouseEvent.movementY Read only
The Y coordinate of the mouse pointer relative to the position of the last mousemove event.
MouseEvent.offsetX Read only
The X coordinate of the mouse pointer relative to the position of the padding edge of the target node..
MouseEvent.offsetY Read only
The Y coordinate of the mouse pointer relative to the position of the padding edge of the target node.
MouseEvent.pageX Read only
The X coordinate of the mouse pointer relative to the whole document.
MouseEvent.pageY Read only
The Y coordinate of the mouse pointer relative to the whole document.
MouseEvent.region Read only
Returns the id of the hit region affected by the event. If no hit region is affected, null is returned.
MouseEvent.relatedTarget Read only

The secondary target for the event, if there is one.

MouseEvent.screenX Read only
The X coordinate of the mouse pointer in global (screen) coordinates.
MouseEvent.screenY Read only
The Y coordinate of the mouse pointer in global (screen) coordinates.
MouseEvent.shiftKey Read only
Returns true if the shift key was down when the mouse event was fired.
MouseEvent.which Read only
The button being pressed when the mouse event was fired.
MouseEvent.mozPressure Read only
The amount of pressure applied to a touch or tablet device when generating the event; this value ranges between 0.0 (minimum pressure) and 1.0 (maximum pressure).
MouseEvent.mozInputSource Read only

The type of device that generated the event (one of the MOZ_SOURCE_* constants listed below). This lets you, for example, determine whether a mouse event was generated by an actual mouse or by a touch event (which might affect the degree of accuracy with which you interpret the coordinates associated with the event). The possible values are:

Constant name Value Desription
MouseEvent.MOZ_SOURCE_UNKNOWN 0 The input device is unknown.
MouseEvent.MOZ_SOURCE_MOUSE 1 The event was generated by a mouse (or mouse-like device).
MouseEvent.MOZ_SOURCE_PEN 2 The event was generated by a pen on a tablet.
MouseEvent.MOZ_SOURCE_ERASER 3 The event was generated by an eraser on a tablet.
MouseEvent.MOZ_SOURCE_CURSOR 4 The event was generated by a cursor.
MouseEvent.MOZ_SOURCE_TOUCH 5 The event was generated on a touch interface.
MouseEvent.MOZ_SOURCE_KEYBOARD 6 The event was generated by a keyboard.
MouseEvent.x Read only
Alias for MouseEvent.clientX.
MouseEvent.y Read only
Alias for MouseEvent.clientY

Methods

This interface also inherits methods of its parents, UIEvent and Event.

MouseEvent.getModifierState()
Returns the current state of the specified modifier key. See the KeyboardEvent.getModifierState() for details.
MouseEvent.initMouseEvent()
Initializes the value of a MouseEvent created. If the event has already being dispatched, this method does nothing.

Example

This example demonstrates simulating a click (that is programmatically generating a click event) on a checkbox using DOM methods. 

function simulateClick() {
  var evt = new MouseEvent("click", {
    bubbles: true,
    cancelable: true,
    view: window,
  });
  var cb = document.getElementById("checkbox"); //element to click on
  var canceled = !cb.dispatchEvent(evt);
  if(canceled) {
    // A handler called preventDefault
    alert("canceled");
  } else {
    // None of the handlers called preventDefault
    alert("not canceled");
  }
}
document.getElementById("button").addEventListener('click', simulateClick);
<p><label><input type="checkbox" id="checkbox"> Checked</label>
<p><button id="button">Click me</button>

Click on the button to see how the sample works:

Specifications

Specification Status Comment
WHATWG HTML Living Standard
The definition of 'MouseEvent.region' in that specification.
Living Standard From Document Object Model (DOM) Level 3 Events Specification, added the region property.
Pointer Lock
The definition of 'MouseEvent' in that specification.
Candidate Recommendation From Document Object Model (DOM) Level 3 Events Specification, added movementX and movementY properties.
CSS Object Model (CSSOM) View Module
The definition of 'MouseEvent' in that specification.
Working Draft From Document Object Model (DOM) Level 3 Events Specification, added offsetX and offsetY, pageX and pageY, x, and y properties.
Document Object Model (DOM) Level 3 Events Specification
The definition of 'MouseEvent' in that specification.
Working Draft From Document Object Model (DOM) Level 2 Events Specification, added the MouseEvent() constructor, the getModifierState() method and the buttons property.
Document Object Model (DOM) Level 2 Events Specification
The definition of 'MouseEvent' in that specification.
Recommendation Initial definition.

Browser compatibility

Feature Firefox (Gecko) Chrome Internet Explorer Opera Safari
Basic support (Yes) (Yes) (Yes) (Yes) (Yes)
movementX
movementY
(Yes) moz (Yes) webkit ? ? ?
buttons (Yes) Not supported ? ? ?
which 1.0 1.0 9.0 5.0 1.0
getModifierState() 15 (15) (Yes) (Yes) (Yes) (Yes)
mozPressure and mozInputSource 4.0 (2) Not supported Not supported Not supported Not supported
MouseEvent() 11 (11) (Yes) ? (Yes) ?
MouseEvent.region 32 (32) ? ? ? ?
MouseEvent.offsetX, and MouseEvent.offsetY 40 (40) ? ? ? ?
Feature Firefox Mobile (Gecko) Android IE Mobile Opera Mobile Safari Mobile
Basic support ? ? ? ? ?

See also

Document Tags and Contributors

Last updated by: cvrebert,