Why your Mac sleeps while running Unity
Unity builds, asset imports, and lightmap bakes can take hours. The Editor may be running but if you're not actively using the mouse, macOS can sleep mid-bake.
macOS tracks idle time based on mouse and keyboard input, not CPU or app activity. If you're not actively moving the mouse while Unity does its thing, the idle timer counts down and your Mac sleeps.
Keep your Mac awake with Shake It On
Shake It On moves your mouse slightly at regular intervals, resetting the idle timer. It only runs when your conditions are met, so it activates when Unity is working and stops when you're done.
Best condition for Unity: Only Shake If CPU is above 20%
Quick setup
- Install Shake It On and grant Accessibility permission
- Open Settings from the menu bar icon
- Under "Only Shake If," enable the condition: Only Shake If CPU is above 20%
- Under "Paused When," enable "On battery" to save power when unplugged
- For long overnight operations, enable "Allow display to sleep" in the General section so the screen turns off but the system stays awake