Element: mousedown 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.

The mousedown event is fired at an Element when a pointing device button is pressed while the pointer is inside the element.

This differs from the click event in that click is fired after a full click action occurs; that is, the mouse button is pressed and released while the pointer remains inside the same element. mousedown is fired the moment the button is initially pressed.

This behavior is different from pointerdown events. When using a physical mouse, mousedown events fire whenever any button on a mouse is pressed down. pointerdown events fire only upon the first button press; subsequent button presses don't fire pointerdown events.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

addEventListener("mousedown", (event) => { })

onmousedown = (event) => { }

Event type

A MouseEvent. Inherits from UIEvent and Event.

Event 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 (if applicable) when the mouse event was fired.
MouseEvent.buttons Read only: The buttons being pressed (if any) when the mouse event was fired.
MouseEvent.clientX Read only: The X coordinate of the mouse pointer in viewport coordinates.
MouseEvent.clientY Read only: The Y coordinate of the mouse pointer in viewport coordinates.
MouseEvent.ctrlKey Read only: Returns true if the control key was down when the mouse event was fired.
MouseEvent.layerX Non-standard Read only: Returns the horizontal coordinate of the event relative to the current layer.
MouseEvent.layerY Non-standard Read only: Returns the vertical coordinate of the event relative to the current layer.
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.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 screen coordinates.
MouseEvent.screenY Read only: The Y coordinate of the mouse pointer in screen coordinates.
MouseEvent.shiftKey Read only: Returns true if the shift key was down when the mouse event was fired.
MouseEvent.mozInputSource Non-standard Read only: The type of device that generated the event (one of the MOZ_SOURCE_* constants). 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).
MouseEvent.webkitForce Non-standard Read only: The amount of pressure applied when clicking.
MouseEvent.x Read only: Alias for MouseEvent.clientX.
MouseEvent.y Read only: Alias for MouseEvent.clientY.