Closed-Lid Mode

Closed-lid mode in Shake It On

macOS sleeps your MacBook when you close the lid. That's almost always what you want. Almost.

If you're using your MacBook as a "desktop replacement" — docked with an external display and power adapter, lid closed because it's in a stand — you want the opposite. Close the lid, keep working. Closed-lid mode in Shake It On 1.1.0 enables exactly that.

The IOKit assertion

Closed-lid mode holds a stronger IOKit power assertion than Allow-display-to-sleep: kIOPMAssertionTypePreventSystemSleep. It tells macOS to keep the system awake even when lid-closure events are signaled.

macOS only honors this assertion when:

An external display is connected
The Mac is on power (the adapter, not the battery)

Without those, the toggle is a no-op — your Mac will still sleep on lid close, which is the safe behavior. Apple won't let any app bypass the thermal-protection logic.

Closed-lid mode ships in Shake It On 1.1.0. Pair with an external display + power, close the lid, keep working.

Enable Closed-lid mode

Plug in a power adapter and connect an external display.
Open Settings (menu bar → Settings…).
Scroll to the General section.
Turn on Keep awake when lid is closed.

Close the lid. The Mac stays awake. Open it back up — also fine, nothing changes.

vs. Allow display to sleep

These are two different IOKit assertions for two different cases:

Allow display to sleep — keeps the system awake; the display can dim and sleep. Lid stays open. Use this for overnight renders on a stationary Mac.
Closed-lid mode — keeps the system awake even when the lid is closed. Use this for docked-MacBook setups.

You can turn both on. Closed-lid takes priority because it's the stronger assertion.

A note on thermals

Running a MacBook with the lid closed restricts airflow. For light workloads (writing, video calls, web) it's fine. For sustained heavy CPU (rendering, encoding, training a model) you may want the lid open even with closed-lid mode toggled on.

Important

On an iMac, Mac Studio, or Mac mini, the toggle is harmless — there's no lid to close. Leave it on or off; it doesn't matter.

vs. Amphetamine's closed-display mode

Amphetamine has the same feature; they call it "Closed-Display Mode." On Apple Silicon, Amphetamine recommends a "Power Protect" workaround for some cases. Shake It On uses the same IOKit assertion type natively without any workaround, on both Apple Silicon and Intel.

Keep your Mac awake the easy way.

Shake It On lives in your menu bar and uses organic mouse movement to prevent sleep. Set it once and forget it.

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Shake It On Closed-Lid Mode