Low Power Mode on a Mac: how to turn it on, and from Terminal
Low Power Mode lowers the Mac's speed and brightness to stretch the battery. How to turn it on in settings or with pmset, and when it is worth it.
What does Low Power Mode do?
It reduces system clock speed and screen brightness and cuts back some background activity, so the Mac draws less power. Everyday work feels much the same; heavy work such as exports and builds takes longer.
How do I turn it on?
System Settings, Battery, Low Power Mode: Never, Always, Only on Battery, or Only on Power Adapter. Or from Terminal:
pmset -g | grep lowpowermode # ours: 0, off
sudo pmset -b lowpowermode 1 # on, battery only
sudo pmset -a lowpowermode 0 # off everywhereOnly on Battery is the sensible default for most laptops: full speed plugged in, longer range unplugged.
Is it worth it?
It helps most when the drain is steady background work. When one app is causing the drain, quitting that app saves far more; see what is draining your battery.
See it live
Free Mac's System tab shows what the Mac is drawing from the adapter and the battery, and ranks what is draining it by energy impact, every second. See also pmset settings.
Related: powerd and energy impact mean.
Common questions
How do I turn on Low Power Mode on a Mac?
System Settings, Battery, Low Power Mode, or sudo pmset -b lowpowermode 1 for battery only.
Does Low Power Mode slow my Mac down?
Yes, for heavy work such as exports and builds. Everyday tasks feel much the same.
Can Low Power Mode be on only when unplugged?
Yes. Choose Only on Battery in Battery settings.