What does Low Power Mode do on a Mac?

What Low Power Mode does

Apple's current description is short: Low Power Mode "reduces energy use to increase battery life" (Apple, About Power Modes on your Mac). When the feature arrived in macOS 12 Monterey in 2021, Apple's features page was more specific: it "reduces system clock speed and display brightness to extend battery life" (Apple's macOS Monterey features page, archived November 2021).

macOS 15.1 Sequoia added two things. On Macs with fans, Low Power Mode "also helps reduce fan noise for tasks done in quieter environments", and on a Mac that's always left on, such as a Mac mini used as a home server, it "allows reduced power consumption" (Apple).

What that means in practice:

• Work that keeps the chip busy takes longer. Exporting video, compiling code, rendering, games and big photo edits all depend on clock speed, so they run slower. In exchange, the Mac draws less power while it works, and runs cooler and quieter.
• Light work changes less. Reading, writing and browsing leave the chip idle most of the time, so a lower top speed is less noticeable. The dimmer display still saves power.
• It isn't a charging setting. Apple says power modes "can be used whether your Mac is connected to power or not", and describes no effect on charging. How far and when the battery charges is up to Optimized Battery Charging and, on macOS 26.4 and later, Charge Limit.

Apple doesn't publish how much longer the battery lasts in Low Power Mode, or how much slower a Mac gets. Both depend on what you're doing, which is why it's worth measuring on your own Mac (see below).

Which Macs have Low Power Mode

On Mac laptops, Low Power Mode sits in Battery settings. Apple's guide to Battery settings on a Mac laptop lists it, with the note that "some of the options may not be available, depending on your Mac".

For the full macOS 15.1 version, with lower power for always-on use and quieter fans, Apple's Power Modes article gives a model list. In its words, "You can use Low Power Mode with reduced power consumption and reduced fan noise (on models with an active cooling system) on the following models":

If your MacBook isn't on that list, look in System Settings › Battery anyway: the list is for the version with the macOS 15.1 additions, while Apple's Battery settings guide lists Low Power Mode for Mac laptops in general.

The opposite setting, High Power Mode, lets the fans run faster so the chip can hold its speed through long, heavy work. Apple lists it for the MacBook Pro introduced in 2024 or later with a Pro or Max chip, the 2021 to 2023 MacBook Pro with a Max chip, the Mac mini introduced in 2024 or later with a Pro chip, and the Mac Studio introduced in 2026.

How to turn on Low Power Mode on a Mac

The steps are the same on macOS 15 Sequoia, macOS 26 Tahoe and macOS 27:

1. Open System Settings and click Battery in the sidebar. On a desktop Mac, click Energy.
2. Depending on your Mac, you'll see either a Low Power Mode option, or an Energy Mode section with two pop-up menus, On battery and On power adapter.
3. Choose Low Power Mode. With Energy Mode, set it for On battery and Low Power Mode switches on by itself whenever you unplug; On power adapter keeps its own setting.

By default a Mac uses Automatic, which Apple describes as balancing "energy use and performance". Switch back the same way at any time.

Two shortcuts:

• Control Center. Apple says that "in macOS Sequoia 15.1 or later, you can also select Energy Modes from Control Center".
• The battery menu. To check which mode is on, click the battery icon in the menu bar (Apple). To keep the mode visible next to the icon on macOS 26 and 27, open System Settings › Menu Bar, select Battery, click Battery Options and choose an option next to Show Energy Mode. On macOS 15, the same choice is under System Settings › Control Center › Battery, once Battery is shown in the menu bar (Apple's macOS 27 and macOS 15 guides).

Check it from Terminal

If you'd rather check than click, this prints the current power settings. It only reads, needs no password and changes nothing:

pmset -g custom

Trimmed output from the M2 Max MacBook Pro we used for this guide (macOS 27.0.1), which is set to Low Power Mode on battery and Automatic on the adapter:

Battery Power:
 lowpowermode         1
 displaysleep         5
AC Power:
 lowpowermode         0
 displaysleep         30

1 means Low Power Mode is on for that power source and 0 means it's off. pmset -g shows the settings in use right now. The pmset manual page doesn't document lowpowermode, and changing any pmset setting needs an administrator password, so use System Settings to turn it on or off.

When to use it, and when to leave it off

Low Power Mode is worth turning on:

• for a long day away from a charger, or a flight, when finishing the day matters more than speed;
• in a quiet room, on a Mac with fans, if fan noise bothers you more than slower exports;
• on a desktop Mac that's on all the time and mostly idle, where Apple says it reduces power use.

It's worth leaving off when you're waiting on the Mac: a long export, a build or a game. A slower chip uses less power per second but takes more seconds, so for a fixed job the energy saved can be smaller than you'd expect, and you wait longer. If you do heavy work on the adapter with a MacBook Pro that supports it, High Power Mode is the setting for that.

Leaving Low Power Mode on all the time is a supported choice: Apple's settings offer it for both battery and adapter, and Apple gives no warning against it. The cost is performance.

Other settings that save battery alongside it

Low Power Mode is one switch among several in the same Battery settings. Apple's guide lists these among the additional options, behind the Options button (macOS 15, 26 and 27):

• Slightly dim the display on battery: "Conserve energy by dimming the display when your Mac is not plugged in."
• Optimize video streaming while on battery: plays HDR video in standard dynamic range, "which requires less energy".

Apple's battery tips add the basics: "Dim the screen to the lowest comfortable level to achieve maximum battery life", and disconnect peripherals and quit apps you aren't using (Apple, Batteries: Maximizing Performance). Charge Limit is a different kind of setting: it's about how fast the battery wears, not how long a charge lasts. Should I use a charge limit? covers that, and why your MacBook battery drains fast covers the apps and habits behind short runtimes.

Measure the difference yourself

Since Apple gives no figures, the honest answer to "how much does it save?" is: measure it on your Mac, with your work. Do the same thing twice, once in Automatic and once in Low Power Mode, on battery, at a similar brightness:

1. Pick something repeatable: a 10-minute video, a set of web pages, or an export you can time.
2. Note the battery percentage before and after each run, or watch the power draw while it runs.
3. Compare the drop, and how long each run took.

For the power draw, Activity Monitor's Energy tab shows Energy Impact, which Apple calls "a relative measure", not watts. How many watts does a MacBook use? shows how to read the whole Mac's draw in watts from Terminal, with our own readings.

How Tend helps

Tend can show the whole Mac's draw in watts right in the menu bar (Settings › General › Menu bar shows › Watts), so the before-and-after test above takes a glance rather than a calculation. Its Energy & Apps list shows each app's estimated share in watts, which tells you whether one app, rather than the power mode, is what's costing you battery. Both are free. Tend can't switch Low Power Mode for you: macOS gives apps no way to change it without an administrator password.

Questions

Related guides

Sources

• Apple, About Power Modes on your Mac (published 21 September 2026)
• Apple, Change Battery settings on a Mac laptop (macOS 15, 26 and 27 versions)
• Apple, Monitor your Mac laptop's battery (macOS 15 and 27 versions)
• Apple, macOS Monterey features (archived copy, November 2021)
• Apple, Batteries: Maximizing Performance
• Apple, View energy consumption in Activity Monitor on Mac
• man pmset and pmset -g custom on a MacBook Pro (M2 Max) with macOS 27.0.1, 20 October 2026

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