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/DOM

window.innerWidth

Width (in pixels) of the browser window viewport including, if rendered, the vertical scrollbar.

Note: If you use nsIDOMWindowUtils.setCSSViewport() to set the virtual window size for page layout purposes, the value returned by this property corresponds to the viewport width set using that method.

Syntax

var intViewportWidth = window.innerWidth;

Value

intViewportWidth stores the window.innerWidth property value.

The window.innerWidth property is read only; it has no default value.

Notes

The innerWidth property is supported in any window object like a window, a frame, a frameset, or a secondary window.

There is an algorithm to obtain the width of the viewport excluding, if rendered, the vertical scrollbar.

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;

To change the size of a window, see window.resizeBy and window.resizeTo.

Specification

Specification	Status	Comment
CSS Object Model (CSSOM) View Module The definition of 'window.innerWidth' in that specification.	Working Draft	Initial definition

Browser compatibility

Feature	Chrome	Edge	Firefox (Gecko)	Internet Explorer	Opera	Safari
Basic support	1	(Yes)	1.0 (1.7 or earlier)^[1]	9	9	3

Feature	Android	Edge	Firefox Mobile (Gecko)	IE Mobile	Opera Mobile	Safari Mobile
Basic support	1	(Yes)	1.0 (1.0)^[1]	9	9	3

[1] From Firefox 4 to 24, this property was buggy and could give a wrong value before page load on certain circumstances, see bug 641188.