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.