What WattMate does

Updated 30 September 2026 · each page below quotes the wording the app actually shows, taken from its own strings. Who measures this.

Three measurements WattMate makes, and a matching set of sentences for the times a measurement cannot be made. The refusals are the part worth reading: they are what separates a number from a guess wearing a number's clothes.

The three

Watts per app Every app in watts instead of a unitless score, with helper processes folded into one row and system daemons kept out of the ranking. Chrome's forty processes appear once. On a machine without the kernel counter there is no list at all, and the app says so rather than showing zeros. The quit receipt What quitting an app is worth, stated as minutes before you do it, then checked two minutes afterwards against what the machine actually did. Including the answer nobody else prints: the effect could not be isolated, so nothing is claimed. Where the adapter's watts go Delivered, eaten, stored, spare. And when the Mac wants more than the charger gives, the shortfall named in watts next to the app responsible.

One app, kept in sight

The favourite Star one app and it sits first in the list and gets its own item in the menu bar, icon and watts beside the battery. Click it for a verdict on the last hour: behaving as usual, above its usual since a given time, using power in the background, or running away. A notification when it stays over a line you set, once per spell. New in 1.4.

The item in the menu bar

WattMate's own item is a battery drawn the way macOS drew it before 27: an outline with the charge filled in, the nub on the end, and the percentage beside it as the same whole number macOS prints. It is drawn on the pixel grid so it sits level with the system icons. If you would rather keep one battery in the menu bar, switch the system icon off in Control Center settings and leave this one; the percentage is a toggle in WattMate's Settings, under The app. The screenshots on this site show the popover the way it opens, under that item.

What is deliberately missing

No charge limiting. Since macOS 26.4, Apple silicon Macs cap charging natively. A second switch beside Apple's own would be a feature for a feature list rather than for you.

No Intel support. The per-process energy counter compiles on Intel and silently returns zero, so the app would ship a number that is always wrong.

No success rate for its own predictions. Publishing "our estimates hold N% of the time" would need a corpus we do not have yet, and the whole point of the receipt is not inventing figures.

Questions people ask

What does it need to run?

macOS 14 or later on Apple silicon. It reads counters the system already exposes, so there is no password prompt and no helper to install.

Does anything leave the Mac?

Your per-app measurements do not. Measurement and storage are local, there is no account, and no per-app data is sent anywhere. Anonymous usage statistics and crash reports are sent by default, and one switch in Settings turns both off; a licence check runs only if you buy, and the app asks our own site whether an update exists. The privacy page lists what is stored and everything that leaves.

How long before it shows numbers?

The app list appears within seconds. The minutes need a run of measurement windows: half the time the first figure arrives within about three minutes, sometimes longer, which is why the app never shows a countdown.

Is there a free version?

Part of it. The list of apps, their watts, the battery's own health readings, the last run and the most recent night stay free. The minutes, the depth of the run journal, the archive of nights and the totals need a key, $9.99 a year or $29 once, after a ten-day trial of everything that starts the first time you open the app.