The clientX read-only property of the MouseEvent interface provides the horizontal 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 clientX value of 0, regardless of whether the page is scrolled horizontally. 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.


var x = instanceOfMouseEvent.clientX

Return value

A number


<!DOCTYPE html> 
    <title>clientX/clientY example</title>

      function showCoords(evt){
          "clientX value: " + evt.clientX + "\n" +
          "clientY value: " + evt.clientY + "\n"
  <body onmousedown="showCoords(event)">
    <p>To display the mouse coordinates click anywhere on the page.</p>


Specification Status Comment
CSS Object Model (CSSOM) View Module
The definition of 'clientX' in that specification.
Working Draft Redefines MouseEvent from long to double
Document Object Model (DOM) Level 3 Events Specification
The definition of 'MouseEvent.clientX' 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.clientX' in that specification.
Obsolete Initial definition.

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung Internet
Basic supportChrome Full support YesEdge Full support YesFirefox Full support YesIE Full support 6Opera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support YesOpera Android Full support YesSafari iOS Full support YesSamsung Internet Android ?
Value type changed from long to doubleChrome Full support 56Edge ? Firefox ? IE ? Opera ? Safari ? WebView Android Full support 56Chrome Android Full support 56Edge Mobile ? Firefox Android ? Opera Android ? Safari iOS ? Samsung Internet Android ?


Full support  
Full support
Compatibility unknown  
Compatibility unknown

See also

Document Tags and Contributors

Last updated by: fscholz,