Move windows around on a Mac with keyboard shortcuts and SizeUp

20090608spaces-11-1Some utilities fill their niche so well that they quickly become an indispensable part of your daily computer use and SizeUp is one program that falls into that category for me.

The concept is simple enough — this tiny program (4.1Mb) lets you resize and position windows on the Mac OS Desktop using keyboard shortcuts — and some new features added by its most recent update prompted me to write a bit about it.

SizeUp’s splits your Mac screen into four equal partitions and customisable keyboard shortcuts let you move and resize the active window (Finder or application) to fill that partition. One set of shortcuts sends windows to one of the four screen corners (or ‘quadrants’), while a second sends windows to one of the four halves of the screen. In other words, SizeUp provides a quick and easy way to tile windows on the Desktop to give an organised workspace — something that Windows users have been able to do with a right-click on the Taskbar since Windows 95.


If you like a tidy Desktop, SizeUp is a much easier way to obtain it than dragging and resizing windows with the mouse. At the moment, I have Scrivener open on the right half of my screen and two Finder windows stacked on on top of the other on the left — all achieved with just a few key-presses. It also means that you don’t need to move your hands away from the keyboard to move windows around and like any keyboard shortcut, SizeUp’s can almost be used subconsciously.

If you need to grab screenshots regularly, SizeUp’s ability to centre a window on-screen and resize it to a pre-defined size is also invaluable (1024 x 768 is a common requirement for screenshots for use in magazines). The ‘full-screen’ shortcut is also a handy solution to the unpredictable behaviour of the Mac OS  ‘+’ button, which may placate some recent Windows switchers…

SizeUp can also be used to move windows between screens on a dual-monitor set-up (similar to UltraMon for Windows) and the recent 1.2 update now offers shortcuts for moving windows between Spaces, too. SizeUp 1.2 also adds a few cosmetic tweaks — you can now specify a pixel margin between windows, as well as around the edge of the screen (to space-out tiled windows); you can use either pixel dimensions or a screen percentage when centering windows; and there’s the option to resize windows proportionally when moving windows between screens with different resolutions.


SizeUp 1.2 also lets you change the dimensions of the screen corners and halves, so you can split the left and right ‘halves’ of the screen 70/30, for example, rather than the default 50/50. I’d also like the option to resize windows to something less than 50% no matter where they’re moved to, so that a window stays at 30% width both on the left and right of the screen, for instance. Maybe this will make it into v1.3.

Developer Irradiated Software offers an interesting deal for SizeUp — it suggests you pay $12.99, but you’re free to lower this to $4.99 if you feel the program isn’t worth it (or if you’re just tight). You can also install the program on as many Macs as you like. Alternatively, there’s a free TwoUp application that just puts window in the four screen halves if that’s all you need.

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