Web/API/MouseEvent/screenX

The screenX read-only property of the MouseEvent interface provides the horizontal coordinate (offset) of the mouse pointer in global (screen) coordinates.

Syntax

var x = instanceOfMouseEvent.screenX

Return value

A double floating point value. Early versions of the spec defined this as an integer referring to the number of pixels. 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

Routing an event

When you trap events on the window, document, or other roomy elements, you can get the coordinates of that event (e.g., a click) and route it properly, as the following example demonstrates:

function checkClickMap(e) {
  if (e.screenX < 50) doRedButton();
  if (50 <= e.screenX && e.screenX < 100) doYellowButton();
  if (e.screenX >= 100) doRedButton();
}

Specifications

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

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`screenX`	Chrome Full support Yes	Edge Full support 12	Firefox Full support Yes	IE Full support 9	Opera Full support Yes	Safari Full support Yes	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android Full support Yes	Opera Android Full support Yes	Safari iOS Full support Yes	Samsung Internet Android Full support Yes
Value type changed from `long` to `double`	Chrome Full support 56	Edge Full support ≤79	Firefox ?	IE ?	Opera ?	Safari ?	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android ?	Opera Android ?	Safari iOS ?	Samsung Internet Android Full support 6.0

Legend

Full support: Full support
Compatibility unknown: Compatibility unknown