Web/API/Window/resizeBy

The Window.resizeBy() method resizes the current window by a specified amount.

Syntax

window.resizeBy(xDelta, yDelta) 

Parameters

• xDelta is the number of pixels to grow the window horizontally.
• yDelta is the number of pixels to grow the window vertically.

Example

// Shrink the window 
window.resizeBy(-200, -200);

Notes

This method resizes the window relative to its current size. To resize the window in absolute terms, use window.resizeTo().

Creating and resizing an external window

 

For security reasons, it's no longer possible in Firefox for a website to change the default size of a window in a browser if the window wasn’t created by window.open(), or contains more than one tab. See the compatability table for details on the change.

Even if you create window by window.open() it is not resizable by default. To make the window resizable, you must open it with the "resizable" feature.

 

// Create resizable window
myExternalWindow = window.open("http://myurl.domain", "myWindowName", "resizable");

// Resize window to 500x500
myExternalWindow.resizeTo(500, 500);

// Make window relatively smaller to 400x400
myExternalWindow.resizeBy(-100, -100);

The window you create must respect the Same Origin Policy. If the window you open is not in the same orgin as the current window, you will not be able to resize, or access any information on, that window/tab.

Specifications

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

Browser compatibility

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

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
resizeBy	Chrome Full support 1	Edge Full support 12	Firefox Full support 1 Notes' Full support 1 Notes' Notes' Since Firefox 7, it's no longer possible for a web site to change the default size of a window in a browser if the window wasn't created by window.open or contains more than one tab. See here for more details.	IE Full support 4	Opera Full support ≤12.1	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support ≤12.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0

Legend

Full support  

Full support

See implementation notes.'

See implementation notes.

Window.resizeBy() by Mozilla Contributors is licensed under CC-BY-SA 2.5.