The WheelEvent.deltaY read-only property is a double representing the vertical scroll amount in the WheelEvent.deltaMode unit.


var dY = event.deltaY;


var syntheticEvent = new WheelEvent("syntheticWheel", {"deltaY": 4, "deltaMode": 0});



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

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
deltaYChrome Full support 31Edge Full support 12Firefox Full support 17IE Full support 9
Full support 9
Notes IE9 supports an old draft of the spec where this value was a long instead of a double.
Opera Full support 18Safari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 17Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yes


Full support  
Full support
See implementation notes.
See implementation notes.

See also

Document Tags and Contributors

Contributors to this page: mdnwebdocs-bot, fscholz, libbymc, IceCreamYou, teoli
Last updated by: mdnwebdocs-bot,