The clientY read-only property of the MouseEvent interface returns the vertical coordinate within the application's client area at which the event occurred (as opposed to the coordinates within the page). For example, clicking in the top-left corner of the client area will always result in a mouse event with a clientY value of 0, regardless of whether the page is scrolled vertically. Originally, this property was defined as a long integer. The CSSOM View Module redefined it as a double float. See the Browser compatibility section for details.

Syntax

var y = instanceOfMouseEvent.clientY

Return value

A number

Example

<html>
<head>
<title>clientX\clientY example</title>

<script type="text/javascript">
function showCoords(evt){
  alert(
    "clientX value: " + evt.clientX + "\n"
    + "clientY value: " + evt.clientY + "\n"
  );
}
</script>
</head>

<body onmousedown="showCoords(event)">
<p>To display the mouse coordinates click anywhere on the page.</p>
</body>
</html>

Specifications

Specification Status Comment
CSS Object Model (CSSOM) View Module
The definition of 'clientY' in that specification.
Working Draft Redefines MouseEvent from long to double
Document Object Model (DOM) Level 3 Events Specification
The definition of 'MouseEvent.clientY' in that specification.
Obsolete No change from Document Object Model (DOM) Level 2 Events Specification.
Document Object Model (DOM) Level 2 Events Specification
The definition of 'MouseEvent.clientY' in that specification.
Obsolete Initial definition.

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) (Yes) (Yes) 6 (Yes) (Yes)
Redefined from long to double 56 ? ? ? ? ?
Feature Android Webview Chrome for Android Edge Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) ? ? ? ?
Redefined from long to double 56 56 ? ? ? ? ?

See also

Document Tags and Contributors

 Last updated by: jpmedley,