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WheelEvent

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.

* Some parts of this feature may have varying levels of support.

The WheelEvent interface represents events that occur due to the user moving a mouse wheel or similar input device.

Note: This is the standard wheel event interface to use. Old versions of browsers implemented the non-standard and non-cross-browser-compatible MouseWheelEvent and MouseScrollEvent interfaces. Use this interface and avoid the non-standard ones.

Don't confuse the wheel event with the scroll event:

A wheel event doesn't necessarily dispatch a scroll event. For example, the element may be unscrollable at all. Zooming actions using the wheel or trackpad also fire wheel events.
A scroll event isn't necessarily triggered by a wheel event. Elements can also be scrolled by using the keyboard, dragging a scrollbar, or using JavaScript.
Even when the wheel event does trigger scrolling, the delta* values in the wheel event don't necessarily reflect the content's scrolling direction.

Constructor

WheelEvent(): Creates a WheelEvent object.

Instance properties

This interface inherits properties from its ancestors, MouseEvent, UIEvent, and Event.

WheelEvent.deltaX Read only: Returns a double representing the horizontal scroll amount.
WheelEvent.deltaY Read only: Returns a double representing the vertical scroll amount.
WheelEvent.deltaZ Read only: Returns a double representing the scroll amount for the z-axis.
WheelEvent.deltaMode Read only: Returns an unsigned long representing the unit of the delta* values' scroll amount.
WheelEvent.wheelDelta Read only Deprecated Non-standard: Returns an integer (32-bit) representing the distance in pixels.
WheelEvent.wheelDeltaX Read only Deprecated Non-standard: Returns an integer representing the horizontal scroll amount.
WheelEvent.wheelDeltaY Read only Deprecated Non-standard: Returns an integer representing the vertical scroll amount.

Note: Element: mousewheel event has additional documentation about the deprecated properties wheelDelta, wheelDeltaX, wheelDeltaY.

Instance methods

This interface doesn't define any specific methods, but inherits methods from its ancestors, MouseEvent, UIEvent, and Event.

Specifications

Specification
UI Events> # interface-wheelevent>

Browser compatibility