Find what's
draining your Mac
Get your battery back. Which app is draining your Mac right now, in watts, and how many minutes you get back if you quit it.
From the terminal:
brew install --cask wattmateapp/tap/wattmate
10 days of the full app, free, no card, and nothing is charged when they end.
| What you get | Free$0 no key needed |
Pro$9.99 a year or $19 forever (launch price) |
|---|---|---|
| Live watts for apps and coding agents | ||
| See and quit what an agent left running | ||
| Battery health: capacity, cycles, temperature | ||
| Your most recent run and night | ||
| What each app costs in minutes, and what you get back by quitting it | Not included | |
| All runs and nights | Not included | |
| Totals for a week, a month and all time | Not included | |
| How your battery ages, month by month | Not included |
Every app in watts right now, and the minutes you'd get back by quitting one. A coding agent mid-task shows up as a row of its own.
The problem
macOS can rank your apps.
It can't say what you get back
macOS · Activity Monitorthe tool that comes with your Mac
If I quit Safari, what do I get back?
42.3
Safari's Energy Impact. It has no unit, so it can never become minutes. You can rank apps with it, and that is all.
WattMate
If I quit Safari, what do I get back?
24 minutes of battery
2 hr 34 → 2 hr 58
Safari is drawing 7.0 W of the 31.0 W the Mac uses right now: a quarter of everything.
In the menu bar
One click. Everything that's
using power, in watts
Real watts, not a score
Two things here are measured, not guessed: how fast the battery is losing energy, and how much energy the chip is using. The first comes from the battery's own current and voltage; the second from the counters inside the chip.
Minutes, not percentages
A share tells you how the pie is cut. A minute tells you what quitting an app is worth. WattMate takes the time your Mac says is left and shows what it becomes without that app.
Its helpers count too
A browser is 30 processes and a compiler spawns hundreds that live for seconds. They're grouped with the app that started them, so the number next to the name is the whole app.
Star the app you keep an eye on, and it gets its own item in the menu bar, with a verdict on its last hour. How the favourite works ›
Overnight
macOS keeps the list
and never shows it to you
Every wake-up is logged
with the name of whatever asked for it, not powerd or
dasd, which only carry the request, but the app behind it. We read
that log and print the names, with how often each one woke your Mac and for how
long it held it awake.
One Mac, one night: 14% over 11 hours, and the 2 hours that took more than half of it: a phone charging from the sleeping Mac. Yours will read differently. On the second Mac we measured, the wake-ups were 10 times as frequent and a ninth as long. What each wake-up cost we don't know (macOS reports charge in whole percent), so we say how many times and for how long, and nothing more.
The one number
When one app is worth naming, it is
a quarter of everything the Mac uses
26%
Measured, split by model
of the whole Mac goes to the top app in the moments when there is something to name. That is the median across 308 such moments of real work.
+28
Projection
minutes back if you quit it, at 2 hours remaining. A quarter of those moments were worth +16 or less; a quarter, +60 or more.
2.6×
Measured
between a light hour and a heavy one: 4 hr 02 from a full charge against 1 hr 33. What you're doing decides it, not the battery.
The receipt
A promise you can check
Any tool can print a number. 2 minutes after you quit an app, WattMate measures the Mac again (on battery, where power use can be measured) and prints what actually changed.
And when the load moved for other reasons over those 2 minutes, it says so plainly instead of taking the credit. Those quits are not counted toward your total.
The only screen where both halves stand together: what we promised before you quit, and what the Mac actually did after.
New in 1.5
What your coding agent
leaves running
Claude Code, Codex CLI, Gemini CLI and other terminal agents get a row of their own among your apps, in watts like any app.
When a session ends and something it started is still working, such as a watcher or a build that never finished, WattMate names the agent that left it and offers Quit or Keep. It waits 2 minutes after the session first, and a process that only sits idle is left alone.
Every task an agent works through is recorded with the share of the battery it took, and you can be told when a long one finishes.
Each task an agent works through, with its project, branch and the commands it ran, what it drew and what it took from the battery, and where it sits on the power chart.
Over months
Every charge you go through
leaves a record
Detailed data is kept for 2 days and then deleted. The summary of each session is kept indefinitely (until you erase it yourself in Settings), a few dozen bytes that answer "where did yesterday's charge go?" long after the details are gone.
A month of sessions in one list: runs on battery, nights and charges. Pick one and it opens beside the list: how long it lasted, what it cost, how the power ran and which apps it went to.
Plugged in
When the adapter
can't supply enough
Plugged in and still losing charge? That happens when the Mac needs more than the adapter delivers. WattMate says so in watts: the Mac needs 71, the adapter gives 59, and the missing 12 come out of the battery.
It also shows where those watts are going, app by app, and the two things that fix it. macOS shows none of this: it shows a battery icon that stops filling.
What we can and can't measure
The limits are printed
on the box
Graphics has a total, not an owner
Graphics energy is measured as a total. Which app used it is worked out from a GPU counter macOS keeps for each app, which is not the same as time the GPU spent busy: macOS has no per-app energy counter for graphics. The total is exact; the split between apps is not.
The Neural Engine is never blamed
Its energy is measured, but nothing in macOS says which app asked for it. So it is never charged to an app. It stays under its own name, where you can see it.
Rounded against ourselves
An app's power use swings from minute to minute, so the minutes are shown at the low end of what the measurement allows. That is a cautious estimate, not a guarantee: the receipt 2 minutes after you quit shows what you actually got.
It says "Still measuring"
The app list is there from the first seconds; naming the minutes needs more measurements. The screen says exactly that, instead of showing a number that will change.
Sometimes no app is to blame
On a quiet Mac most of the power goes to the screen and to simply being awake (two thirds of it on an M1 Pro we measured in August), and the apps are left with a sliver. In 2 sessions out of 5 there, so little belonged to apps that the session says exactly that: nothing here to close, instead of ranking apps that add up to nothing. A window in front is the exception to watch for: most of what it costs sits outside every per-app counter, so it lands under Screen and system, not on the app's row.
Two pages carry the rest of this: what the app measures and where it stops, and who does the measuring, on which Macs, and what happens when one of our numbers is wrong. If you came here about one specific app, the measured cost of Chrome, Xcode, Telegram, Spotify and Slack is written out window by window.
Pricing
10 days,
then decide
The whole app for 10 days from the moment you open it. No card, no account, nothing to cancel. When they are over the app keeps showing what it measures, and the minutes and the log close.
A year
$9.99
Renews yearly, cancel any time. If it lapses, the paid parts lock again and everything you measured stays where it is.
Buy
Forever
$29 $19
Launch price for the first 100 keys Paid once. The key never expires, and nothing about it renews.
Buy
The price you see is the price you pay. Where VAT applies it is already inside that number, and checkout adds nothing on top.
One key works on two Macs, and a new version works with the key you already have.
Already bought? The key arrives by email from Lemon Squeezy. In WattMate: click the menu bar icon, open Settings…, go to the Licence tab, press Bought already? Enter your key, paste it and press Activate. It works offline for a week if the network is down.
Privacy
Everything is computed
on your Mac
App names, process names and your energy history never leave the machine. There is no account and nothing to sign in to.
Anonymous usage statistics and crash reports are on by default: app version, Mac model, macOS version and counters rounded to steps, tied to a random installation id. One switch in Settings turns them off, and the privacy page lists every event by name.
0.005 W
Measured
is the most the instrument itself cost: 2 mW idle and 4.5 mW while an AI agent worked, a Release build of 1.5 on one Mac, an M3 Max, against 8 to 35 W for the whole machine. Seconds of battery across a working day. That is its own process by the kernel's counter; the menu bar it redraws is drawn by macOS and is not in the figure. The cost of a single measurement tick is guarded by a test.
Questions
Is WattMate in the App Store?
Does quitting apps actually save battery?
Battery health says 96%, so why does a charge only last a few hours?
Why does my Mac lose charge overnight?
Does it work on Intel Macs?
What happens when the year runs out?
Will it be accurate on my Mac?
Does it use much power to run?
See where the hours go
10 days free, no card · Requires macOS 14 or later · Apple silicon
Or from the terminal:
brew install --cask wattmateapp/tap/wattmate