Yet Another Window Resizer

Yet Another Window Resizer is a Firefox extension that lets you resize the browser’s window to whatever size you want.

It is especially useful for web developers and designers who want to be able to quickly see any element in a specific size, for example.

Yet Another Window Resizer comes with the following default resizes, 640x480, 800x600, 1024x768 and 1280x1024. You can, however, add any custom size you want in the program options.

To resize a window using Yet Another Window Resizer you simply have to right click on your mouse and select the 'Resize Window' option.