pmset

CautionPower & sleep settings

pmset -g

Shows/sets power policy. -g assertions reveals what's blocking sleep — the classic no-sleep probe.

Examples

pmset -g assertionsFind what prevents sleep
pmset -g log | grep -e "due to"History of wake reasons
sudo pmset -c displaysleep 15 sleep 30Set display and system sleep times on AC power
sudo pmset repeat wakeorpoweron MTWRF 08:00:00Wake or power on at 08:00 on weekdays
pmset -g schedShow scheduled power events

Syntax

pmset -g [assertions] / pmset sleepnow

Key points

-a applies to all power sources, -b to battery, -c to the power adapter.
When PreventUserIdleSystemSleep is 1 in assertions, the responsible process is listed below it.
Changing settings needs sudo.

When it does not work

If the Mac wakes at night, the text after due to in pmset -g log names the cause (network access and similar).

Before you run it

Changes affect battery behavior.

Used when you see

Mac won't sleep (or wakes up)

Identify assertions blocking sleepThe holder of PreventUserIdleSystemSleep is your culprit.

See the whole flow →

Related commands

caffeinateKeep the Mac awake
powercfgPower & battery diagnostics

The same reference, with no signal at all

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