Web/API/Window/scrollX

The read-only scrollX property of the Window interface returns the number of pixels that the document is currently scrolled horizontally. This value is subpixel precise in modern browsers, meaning that it isn't necessarily a whole number. You can get the number of pixels the document is scrolled vertically from the scrollY property.

Syntax

var x = window.scrollX;

Value

In practice, the returned value is a double-precision floating-point value indicating the number of pixels the document is currently scrolled horizontally from the origin, where a positive value means the content is scrolled to the left. If the document is rendered on a subpixel-precise device, then the returned value is also subpixel-precise and may contain a decimal component. If the document isn't scrolled at all left or right, then scrollX is 0.

If you need an integer value, you can use Math.round() to round it off.

In more technical terms, scrollX returns the X coordinate of the left edge of the current viewport. If there is no viewport, the returned value is 0.

Example

This example checks the current horizontal scroll position of the document. If it's greater than 400 pixels, the window is scrolled back to the beginning.

if (window.scrollX > 400) {
  window.scroll(0,0);
}

Notes

The pageXOffset property is an alias for the scrollX property:

window.pageXOffset == window.scrollX; // always true

For cross-browser compatibility, use window.pageXOffset instead of window.scrollX. Additionally, older versions of Internet Explorer (< 9) do not support either property and must be worked around by checking other non-standard properties. A fully compatible example:

var x = (window.pageXOffset !== undefined)
  ? window.pageXOffset
  : (document.documentElement || document.body.parentNode || document.body).scrollLeft;

var y = (window.pageYOffset !== undefined)
  ? window.pageYOffset
  : (document.documentElement || document.body.parentNode || document.body).scrollTop;

Specification

Specification	Status	Comment
CSS Object Model (CSSOM) View ModuleThe definition of 'window.scrollX' in that specification.	Working Draft

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
`scrollX`	Chrome Full support 1 Full support 1 Full support 1 Alternate Name' Alternate Name' Uses the non-standard name: `pageXOffset`	Edge Full support 12 Full support 12 Full support 12 Alternate Name' Alternate Name' Uses the non-standard name: `pageXOffset`	Firefox Full support 1 Full support 1 Full support 1 Alternate Name' Alternate Name' Uses the non-standard name: `pageXOffset`	IE Full support 9 Alternate Name' Full support 9 Alternate Name' Alternate Name' Uses the non-standard name: `pageXOffset`	Opera Full support 9.6 Full support 9.6 Full support 4 Alternate Name' Alternate Name' Uses the non-standard name: `pageXOffset`	Safari Full support 1 Full support 1 Full support 1 Alternate Name' Alternate Name' Uses the non-standard name: `pageXOffset`	WebView Android Full support 1 Full support 1 Full support 1 Alternate Name' Alternate Name' Uses the non-standard name: `pageXOffset`	Chrome Android Full support 18 Full support 18 Full support 18 Alternate Name' Alternate Name' Uses the non-standard name: `pageXOffset`	Firefox Android Full support 4 Full support 4 Full support 4 Alternate Name' Alternate Name' Uses the non-standard name: `pageXOffset`	Opera Android Full support 10.1 Full support 10.1 Full support 10.1 Alternate Name' Alternate Name' Uses the non-standard name: `pageXOffset`	Safari iOS Full support 1 Full support 1 Full support 1 Alternate Name' Alternate Name' Uses the non-standard name: `pageXOffset`	Samsung Internet Android Full support 1.0 Full support 1.0 Full support 1.0 Alternate Name' Alternate Name' Uses the non-standard name: `pageXOffset`
Subpixel precision	Chrome Full support Yes	Edge Full support ≤18	Firefox Full support 55	IE No support No	Opera Full support Yes	Safari Full support Yes	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android Full support 55	Opera Android ?	Safari iOS ?	Samsung Internet Android Full support Yes

Legend

Full support: Full support
No support: No support
Compatibility unknown: Compatibility unknown
Uses a non-standard name.': Uses a non-standard name.