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WheelEvent

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

Important: 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.

scroll event Please keep in mind that the default action of a wheel event is implementation-defined — a wheel event doesn't necessarily dispatch a scroll event. Even if it does, that doesn't mean that the delta values in the wheel event must reflect the content's scrolling direction. So do not rely on delta properties to get the content's scrolling direction — instead detect value changes of scrollLeft and scrollTop in a scroll event.

Constructor

WheelEvent(): Creates a WheelEvent object.

Properties

This interface inherits properties from its parents, 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. Permitted values are:

Constant	Value	Description
`DOM_DELTA_PIXEL`	`0x00`	The delta values are specified in pixels.
`DOM_DELTA_LINE`	`0x01`	The delta values are specified in lines.
`DOM_DELTA_PAGE`	`0x02`	The delta values are specified in pages.

Methods

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

Specifications

Specification	Status	Comment
Document Object Model (DOM) Level 3 Events Specification The definition of 'WheelEvent' in that specification.	Obsolete	Initial definition.

Browser compatibilityUpdate compatibility data on GitHub

	Desktop
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari
Basic support	31	Yes	17	9	18	Yes
Pinch-to-zoom maps to `WheelEvent` + `ctrl` key.	31	?	55	?	?	Yes
`WheelEvent()` constructor	Yes	Yes	17	No	Yes	Yes
`deltaMode`	31	Yes	17	9	18	Yes
`deltaX`	31	Yes	17	9 9 IE9 supports an old draft of the spec where this value was a `long` instead of a `double`.	18	Yes
`deltaY`	31	Yes	17	9 9 IE9 supports an old draft of the spec where this value was a `long` instead of a `double`.	18	Yes
`deltaZ`	31	Yes	17	9 9 IE9 supports an old draft of the spec where this value was a `long` instead of a `double`.	18	Yes