Enable Single Application Mode in Mac OS X
Single Application Mode is an interesting feature of OS X that is often misunderstood, we’ll discuss what the feature is, how it works, and how to enable it on your Mac running 10.6, 10.7, 10.8, or newer.
What is Single Application Mode?
Single Application Mode is a way to force Mac OS X to show only the application that is currently in use, all other open applications and windows will be minimized into the Dock. Selecting another application from the Dock will then minimize the current application, and the new selection becomes the only thing on screen. I have heard this feature was originally intended for presentation purposes when showing off Mac OS X, but it’s actually a handy way to avoid distractions and maximize screen space on smaller resolution displays.
How to Enable Single Application Mode in Mac OS X
Enabling this feature is done through the command line, so launch the Terminal then enter the following commands exactly:
defaults write com.apple.dock single-app -bool true
For this to take effect, you now must kill the Dock:
Everything will refresh briefly, then just switch an app to see how it works – inactive apps become hidden instantly, revealing only the currently active app in focus.
Turn Off Single App Mode
You can reverse single application mode and get back to multiple application mode easily by changing the original command as follows:
defaults write com.apple.dock single-app -bool false
and again, killing the Dock:
If you ask me, this feature is most useful for those with limited screen real estate or a single monitor, it’s actually kind of obnoxious if you have dual displays on your Mac.
Updated on 5/2/2013 to confirm Single Application Mode still works in OS X 10.7 Lion, and OS X 10.8 Mountain Lion.