MouseEvent.clientX

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 coordinate within the page).

For example, clicking on the left edge 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.

Syntax

var x = instanceOfMouseEvent.clientX

Return value

A double floating point value, as redefined by the CSSOM View Module. Originally, this property was defined as a long integer. See the "Browser compatibility" section for details.

Example

This example displays your mouse's coordinates whenever you trigger the mousemove event.

HTML

<p>Move your mouse to see its position.</p>
<p id="screen-log"></p>

JavaScript

let screenLog = document.querySelector('#screen-log');
document.addEventListener('mousemove', logKey);

function logKey(e) {
  screenLog.innerText = `
    Screen X/Y: ${e.screenX}, ${e.screenY}
    Client X/Y: ${e.clientX}, ${e.clientY}`;
}

Result

Specifications

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
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
clientXChrome Full support 1Edge Full support 12Firefox Full support 1IE Full support 9Opera Full support 10.6Safari Full support 3.1WebView Android Full support 1Chrome Android Full support 18Firefox Android Full support 4Opera Android Full support 11Safari iOS Full support 2Samsung Internet Android Full support 1.0
Value type changed from long to doubleChrome Full support 56Edge Full support ≤79Firefox ? IE ? Opera ? Safari ? WebView Android Full support 56Chrome Android Full support 56Firefox Android ? Opera Android ? Safari iOS ? Samsung Internet Android Full support 6.0

Legend

Full support  
Full support
Compatibility unknown  
Compatibility unknown

See also