macOS service · Power management (macOS)
Why powerd keeps your Mac awake
powerd is the macOS power management service, the part that decides when the Mac sleeps. The assertion you’ll almost always see, “Powerd - Prevent sleep while display is on”, is normal: macOS doesn’t put the Mac to sleep while its display is on. It goes away when the display turns off. It is not the reason a Mac stays awake overnight.
Checked on macOS 27.2.1 on a MacBook Pro with Apple silicon, 11 November 2026.
What you’ll see
| Type | Name | Meaning |
|---|---|---|
PreventUserIdleSystemSleep | Powerd - Prevent sleep while display is on | The display is on, so the Mac stays awake. Released when the display sleeps. |
InternalPreventDisplaySleep | com.apple.powermanagement.delayDisplayOff | A short delay before the display turns off, with a timeout (300 seconds here). |
InternalPreventSleep | com.apple.powermanagement.wakeschedule | Taken briefly around a scheduled wake. |
Check it on your Mac
Open Terminal (in Applications › Utilities) and run:
pmset -g assertions
Real output from the Mac we checked:
pid 418(powerd): [0x00004c9800018a79] 00:54:55 PreventUserIdleSystemSleep named: "Powerd - Prevent sleep while display is on" pid 418(powerd): [0x000057d9001090a8] 00:00:29 InternalPreventDisplaySleep named: "com.apple.powermanagement.delayDisplayOff" Timeout will fire in 270 secs Action=TimeoutActionTurnOff
Activity Monitor shows the same thing without Terminal: open its Energy tab and look at the Preventing Sleep column.
What to do
- Nothing to fix here. If the Mac doesn’t sleep, read the other lines of
pmset -g assertions: an app holdingPreventUserIdleSystemSleeporNoIdleSleepAssertionis the usual cause. - If the display itself never turns off, look for
PreventUserIdleDisplaySleeporNoDisplaySleepAssertionfrom an app, such as a video playing in a browser.
See it without Terminal
SleepPilot, a menu bar app, lists every app that is keeping your Mac awake right now by name — audio through coreaudiod is shown under the app that plays it — and warns you when one holds the Mac awake for too long while nobody is using it. Each morning it can show what kept the Mac awake overnight.
Questions
Is it safe to quit powerd?
No. powerd is part of macOS and can’t be quit.
Is powerd keeping my Mac awake normal?
Normal. Look for other processes in the list instead.
Does powerd keep the display on?
The Mac awake while the display is on.
Other things that keep a Mac awake
- WindowServer — Every key press and mouse move counts as activity, so the idle timer starts again.
- caffeinate — Someone, or a script, asked the Mac to stay awake from Terminal.
- Google Chrome — “Playing audio”, “Video Wake Lock”, “Capturing” or “Download in progress”.
- All of them
- Guide: why won’t my Mac sleep?