On Apple computers, pmset is a command line utility to manipulate power management settings under the Darwin and macOS operating systems. It can assign sleep settings, schedule sleep and wake times, and display power information.
History The pmset utility first appeared in Darwin 6.0.1 and Mac OS X 10.2 "Jaguar". It has been updated periodically since its introduction, and is still available as of Darwin 21.2.0 and macOS Monterey.
Behavior The utility sets or lists power management settings. Some of the functionality provided by the utility is available through the GUI interface of the Energy Saver preference pane. However, pmset allows for greater flexibility and access to several options not available in the GUI.
The utility can set different power management settings depending on usage scenario. Different settings can be applied for when the machine is running off a charger, battery, UPS, or all three. The appropriate flags are as follows:
-c (charger), adjust settings used while connected to a charger -b (battery), adjust settings used when running off a battery -u (UPS), adjust settings used when running off a UPS -a (all, default) adjust settings for all scenarios
Additional arguments be supplied when assigning any power management settings. Power management arguments are discussed in greater detail below. When invoking the command, only specified arguments modify power management options. Any arguments already set will be unmodified by pmset unless those arguments are specifically included.
The utility can schedule wake, sleep, power on or power off events. Events can be recurring based on arbitrary weekday and time combinations, or scheduled for future dates and times. The syntax for scheduling an event is as follows:
pmset [repeat, schedule] [sleep, wake, poweron, shutdown, wakeorpoweron] [<MTWRFSU> <date/time>]
Previously stored events will be overwritten upon running this command. To schedule multiple events they must be entered in one command string. For example, to set a shutdown event every day of the week at 23:59 and a wake or power on event every day of the week at 7:00 enter the following:
sudo pmset repeat shutdown MTWRFSU 23:59:00 wakeorpoweron MTWRFSU 7:00:00
The get flag displays information about the current power management configuration, or a log of recent activity. If no additional arguments are supplied the flag will only display current settings. Additional get arguments are discussed in greater detail below. The get flag is as follows:
-g get, list current power management settings
To view the currently scheduled events type:
pmset -g sched
The utility is also able to configure hibernation and safe sleep options, and change Energy Saver profiles.
Power management settings The pmset utility recognizes the following arguments. Arguments can be passed in serial form in any order. Any bad syntax or unrecognized argument will cause the entire command to fail, resulting in an error message and brief help screen. Power management settings can only be changed by a privileged user.
displaysleep – display sleep timer in minutes, 0 to disable display sleep disksleep – disk spin-down timer in minutes, 0 to disable disk sleep sleep – system sleep timer in minutes, 0 to disable sleep womp - wake on "magic" Ethernet packet, 1 to enable or 0 to disable. Note this setting only appears when running "pmset -g" if the device is plugged into a power source. Otherwise, the womp setting will NOT appear when running "pmset -g". hibernatemode change hibernation mode, 0 for RAM powered while sleeping; 1 for RAM contents written to disk and system totally unpowered; 3 for RAM both powered and written to disk; 5 is the same as mode 1, but for use with secure virtual memory; 7 is the same as mode 3, but for use with secure virtual memory; 25 for hibernation in Mac OS X 10.7, with RAM contents written to disk and system totally unpowered hibernatefile change hibernation image file location; image may only be located on the root volume ring wake on modem ring, 1 to enable or 0 to disable autorestart automatic restart after loss of power, 1 to enable or 0 to disable dps dynamically change processor speed based on load, 1 to enable or 0 to disable reduce permanently reduce processor speed, 1 to enable or 0 to disable powerbutton put the machine to sleep when the power button pressed instead of shutting it down, 1 to enable or 0 to disable powernap lets machine stay up to date even while they're sleeping, 1 to enable or 0 to disable lidwake (laptop only) wake the machine when the laptop lid is opened, 1 to enable or 0 to disable acwake (laptop only) wake the machine when the power source is changed, such as when AC power is removed and the machine switches to battery power, 1 to enable or 0 to disable lessbright (laptop only) slightly turn down display brightness when switching to a specified power source, 1 to enable or 0 to disable halfdim display sleep will use an intermediate half-brightness state between full brightness and fully off, 1 to enable or 0 to disable sms (supported laptops only) use Sudden Motion Sensor to park disk heads on sudden changes in G force, 1 to enable or 0 to disable haltlevel (UPS only) UPS charge in percentage, shut down the machine when UPS reaches a specified charge level haltafter (UPS only) UPS charge in minutes, shut down machine after drawing on UPS for specified number of minutes haltremain (UPS only) UPS charge in minutes, shut down machine when specified time remains on UPS ttyskeepawake prevent idle system sleep when any tty (such as a remote login session) is active; a tty is inactive only when its idle time exceeds the system sleep timer, 1 to enable or 0 to disable autopoweroff (AC power) Where supported, enabled per default as an implementation of Lot 6 to the European Energy-related Products Directive. After sleeping for autopoweroffdelay minutes, the system will write a hibernation image and go into a lower power chipset sleep. Wakeups from this state will take longer than wakeups from regular sleep. The system will not auto power off if any external devices are connected, if the system is on battery power, or if the system is bound to a network and wake for network access is enabled. autopoweroffdelay (AC power) delay before entering autopoweroff mode. (Value = integer, in seconds) standbydelaylow Delay before writing the hibernation image to disk and powering off memory for Standby. standbydelaylow is used when the remaining battery capacity is low. (Value = integer, in seconds) standbydelayhigh Delay before writing the hibernation image to disk and powering off memory for Standby. standbydelayhigh is used when the remaining battery capacity is high. (Value = integer, in seconds) networkoversleep This setting affects how macOS networking presents shared network services during system sleep. This setting is not used by all platforms; changing its value is unsupported. destroyfvkeyonstandby Destroy File Vault Key when going to standby mode. By default File vault keys are retained even when system goes to standby. If the keys are destroyed, user will be prompted to enter the password while coming out of standby mode. (value: 1 - Destroy, 0 - Retain). Since it is essential that the system fully powered down, you also need to set `hibernatemode` to 25 (suspend to disk).
Settings may be adjusted independently for circumstances where the machine is attached to a charger, when running off a battery (in the case of a laptop), or when running off a UPS (if available). Settings can also be adjusted for all four scenarios simultaneously; this is the default option, for when no usage flag is specified. Power management options can be specified for different profiles by appending -c (charger), -b (battery), -u (UPS) or -a (all) flags. The following example will set the machine to sleep after 10 minutes and sleep the display after five minutes, but only when powered by the battery.
pmset -b sleep 10 displaysleep 5
The following command will assign slightly different power management settings for circumstances where the machine is powered by the charger. Here, the machine is set to sleep after 30 minutes and the display is set to never sleep, but only when set by the charger. Issuing both commands will not interfere with each other.
pmset -c sleep 30 displaysleep 0
Arguments can be entered in serial form to set or modify several power management parameters with one command. The following command will set the machine to never sleep (sleep 0), enable the Sudden Motion Sensor (sms 1), set the display to sleep after 20 minutes (displaysleep 20), disable processor speed reduction (reduce 0), enable intermediate display dimness (halfdim 1), enable the machine to wake when the lid is opened (lidwake 1), prevent the system from sleeping when a tty session (such as SSH) is active (ttyskeepawake 1), disable waking the machine when the AC adapter is inserted (acwake 0), disable an automatic restart after power is removed and restored (autorestart 0), enable dynamic change of processor speed based on system load (dps 1), enable wake on modem ring (ring 1), enable wake on receipt of "magic" Ethernet packet (womp 1), and disable hard disk sleep (disksleep 0):
pmset sleep 0 sms 1 displaysleep 20 reduce 0 halfdim 1 lidwake 1 ttyskeepawake 1 acwake 0 autorestart 0 dps 1 ring 1 womp 1 disksleep 0
Because the above example did not include a usage flag, the settings specified will apply to all usage scenarios. Subsequent commands that do specify a usage flag will only affect settings for that usage scenario. For instance, pmset -b sleep 10 will cause the machine to sleep after 10 minutes, but only when the battery is attached. All other settings will apply when the battery is attached, and all settings in the above example will apply when a charger or UPS is attached.
At least as of Darwin 9.4 and OS X 10.5.4 "Leopard", all changes made through pmset are saved in a persistent preferences file at /Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist. This file can be modified manually using the defaults command, but those changes will not be taken up immediately by the power management system. Manual edits of com.apple.PowerManagement.plist also stand the risk of being overwritten. The command pmset touch will reread existing settings from disk and apply them to the system.
With autopoweroff enabled the machine will go into hibernate mode even if hibernatemode is 0. The value of autopoweroffdelay may be in seconds despite the man page (for Mavericks, Nov 9, 2012) documenting it as minutes.
Schedule Settings The pmset command is able to schedule system sleep, shutdown, wakeup or power on events. The schedule argument is for setting up one-time power events, and repeat is for setting up daily or weekly events. Scheduling of events can only be done by a privileged user.
The schedule argument recognizes the following additional arguments:
type; one of sleep, wake, poweron, shutdown or wakeorpoweron date and time (schedule only); in the format "MM/dd/yy HH:mm:ss"; must be in 24-hour format, must be in quotes time (repeat only); in the format HH:mm:ss; must be in 24 format, but does not have to be in quotes weekdays; a subset of MTWRFSU such as M or MTWRF are valid, as are strings weekdays, weekends, and everyday owner; a string describing the person or program who is scheduling the power event (optional)
The utility can be very unforgiving of improper syntax. Any errors in syntax will cause the command to fail and will display a brief help message. The syntax for a scheduled event is as follows:
pmset schedule [sleep, wake, poweron, shutdown, wakeorpoweron] "MM/dd/yy HH:mm:ss"