Does quitting apps actually save battery on a Mac?
Updated 11 November 2026 · Who measures this.
Usually no, and occasionally very much yes. macOS already slows down apps that sit idle out of sight, so quitting them buys almost nothing. But when 1 or 2 processes carry most of the load, like a call app left running after a meeting, quitting that one app can be worth real minutes. Telling the cases apart starts with one measurement.
How do you tell which case you're in?
Look at WattMate's list of apps in watts, not at the Dock. Activity Monitor makes this harder than it should: its Energy Impact column is a number with no unit, and Apple's own documentation calls it a relative measure.
| What you see | What it means | What to do |
|---|---|---|
| The top app takes a large share of what the apps use | That app is the bill | Quit that one app while on battery, then check what the quit gave back |
| Everything is small and even | Quitting gets nothing back | Quit nothing and carry on |
| An app's window is in front, and the list looks calm | Much of what a busy window costs can sit outside the app's own counter | Hide the window and watch the whole Mac's watts |
The last row is the one a list can hide. In our measurements on 4 MacBook Pros the ChatGPT window answering in front cost the whole Mac 1.0 to 4.6 W by voltage times current while its own processes used 0.2 to 0.4 W, and hiding the window took most of that away (the measurements).
Why does the common advice say "no", and is it right?
It is right for an app that sits idle. App Nap slows down apps that are not in front, not updating a visible window and not playing sound, background work gets throttled, and an app that is open but idle costs close to nothing. Quitting 10 of those buys you very little, while costing you relaunch time, lost window state and a browser that reloads the tabs you go back to.
When does quitting an app actually help?
When one app carries most of the load. In our logs, power use across apps is lopsided: most running apps sit near zero while 1 or 2 processes carry the rest, such as a call app left running after a meeting, a browser tab with a busy site, or an app that broke after an update. macOS won't quit a busy app for you: it has no idea the video call ended an hour ago.
We measured both ends in one log on a 14-inch MacBook Pro with M1 Pro: Slack sat at a median of 0.01 W, while Chrome took a median 56% of what the apps used, across 157 measuring windows.
When does quitting apps actively cost you?
When you will reopen the app soon, when a sync client is mid-upload, or when macOS has already napped the app. In each case the quit gives back little, or costs more later than it saved.
- Apps you'll reopen in 10 minutes. Relaunching a heavy app, or a browser restoring 20 tabs, is a burst of work that can cost as much as the quit was supposed to return.
- Sync clients mid-upload. Quit them, and they finish the catch-up later, possibly on battery again.
- Anything macOS already napped. The cost is usually already low, so there's little left to get back.
How do you know a quit worked?
You measure again after it. During the trial or with a key, WattMate estimates what quitting the top app is worth in minutes, and as time left: "+24 min" means "about 2 h 58 m instead of 2 h 34 m". The version from this site then re-measures the Mac a couple of minutes after you quit an app with its Quit button and prints what changed; the App Store version has no Quit button. When other apps spiked at the same moment, it says the effect couldn't be isolated and doesn't count it as a win.
We have not found that follow-up measurement on the pages of Juicy, Mac 4 Breakfast, WhatBattery, BatFi, TurtleBar or Endurance (checked 2 November 2026).
Questions people ask
Should I quit apps every time I unplug?
No. Most of those apps cost close to nothing. Check the list once, quit the one expensive row if there is one, and stop there.
Why does quitting everything sometimes seem to help?
Because somewhere in "everything" was the one app that mattered. You paid with 20 relaunches for one useful quit. Measuring first gets you the same minutes for one click.
Is Activity Monitor enough to find the heavy app?
Sometimes. Its Energy Impact column ranks apps, but the number has no unit, at most a 12-hour average by way of history, and no answer to what a quit is worth in minutes. If the ranking alone settles your case, you don't need anything else.
How it was measured
| Slack and Chrome | One log on a 14-inch MacBook Pro with M1 Pro, macOS 26.3. |
| The window in front | 4 MacBook Pros, voltage times current against the per-process counter: the method. |
| The app list | Checked on 6 Macs under rules, thresholds and scripts published before the first counted run. On all 6, WattMate listed our test programs first (the results). |
What this doesn't show
- How many minutes a quit gives back on your Mac. The checks cover Apple's own power sensor, whether an app's row finds a test program and how much of the Mac's rise it carries. They do not confirm an app's watts as such, nor the battery minutes.
- What an update or a new version of an app changes. The Slack and Chrome figures are from one log.
Related: what the macOS 27 update changes · what "using significant energy" means · what each app costs · how WattMate counts · Mac battery apps by the job they do
Quit one app. The right one.
10 days free, no card · Requires macOS 14 or later · Apple silicon