Window.innerWidth

The read-only Window property innerWidth returns the interior width of the window in pixels. This includes the width of the vertical scroll bar, if one is present.

More precisely, innerWidth returns the width of the window's visual viewport. The interior height of the window—the height of the layout viewport—can be obtained from the innerHeight property.

Syntax

let intViewportWidth = window.innerWidth;

Value

An integer value indicating the width of the window's layout viewport in pixels. This property is read-only, and has no default value.

To change the window's width, use one of the Window methods for resizing windows, such as resizeBy() or resizeTo().

Usage notes

If you need to obtain the width of the window minus the scrollbar and borders, use the root <html> element's clientWidth property instead.

The innerWidth property is available on any window or object that behaves like a window, such as a frame or tab.

Example

// This will return the width of the viewport
var intFrameWidth = window.innerWidth;

// This will return the width of the frame viewport within a frameset
var intFrameWidth = self.innerWidth;

// This will return the width of the viewport of the closest frameset
var intFramesetWidth = parent.innerWidth;

// This will return the width of the viewport of the outermost frameset
var intOuterFramesetWidth = top.innerWidth;

Specifications

Specification
CSSOM View Module (CSSOM View) # dom-window-innerwidth

Browser compatibility

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	WebView Android	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet
`innerWidth`	1	12	1 4-24 This property was buggy and could give a wrong value before page load in certain circumstances, see bug 641188.	9	9	3	1	18	4 4-24 This property was buggy and could give a wrong value before page load in certain circumstances, see bug 641188.	10.1	1 This property returns the width of the visual viewport instead of the layout viewport. See this bug for details.	1.0