Nightwatch for Mac

What you’ll find out

The night, from dusk to dawn.

Nightwatch reads the power history macOS already keeps and turns it into a short, plain-English story of each night.

🌙

A score for every night

One sentence — how long it slept, how often it woke, how much charge it lost — plus a 0–100 rest score you can compare night to night.

📊

A timeline you can read

A band coloured by state — asleep, dark wake, awake with the screen off, screen on — with the battery level drawn over it.

⏰

What woke it

Raw wake codes like rtc/Maintenance or E_RX_IP_PACKET become “Power Nap” or “Network keep-alive”. The original line is one click away.

✋

What kept it up

Apps and services that blocked sleep while your screen was off, ranked by how long they held on.

⚡️

Energy by app

While it runs, Nightwatch samples each app’s energy use and splits the overnight drain between them. Clearly labelled as an estimate.

👀

Right now

See which apps are stopping sleep at this moment, and quit a misbehaving one — after you confirm.

🔋

Battery health

Charge, cycle count, capacity versus new, temperature, and a chart of how much each night cost.

🗓

History that lasts

macOS forgets after about a week. Nightwatch keeps each night it reads, so you can look back over 7 or 30 nights.

🧭

In your menu bar

Last night’s summary at a glance. The moon changes when something is keeping your Mac awake.

How it works

No root, no kernel extension, no guessing.

Every Mac records sleeps, wakes and their reasons in its power log. Nightwatch reads it with pmset -g log, checks live sleep blockers with pmset -g assertions, and reads battery details from the system.

Pick your night window in Settings (11 PM to 7 AM by default). For per-app energy, let Nightwatch open at login so it can take a sample every few minutes overnight. Nightwatch never changes your power settings.

Raw log in, plain English out

EC.LidOpenYou opened the lidYOU

rtc/Maint…Maintenance / Power NapDARK WAKE

ARPTNetwork keep-alive (Wi-Fi)DARK WAKE

Prevent…SleepMusic kept it awake 43 mKEPT UP

FAQ

Questions, answered.

What’s a “dark wake”?

Your Mac briefly wakes with the screen off to check mail, sync, back up or keep network connections alive, then goes back to sleep. A few are normal; dozens a night are worth a look.

Why is the energy-by-app section empty?

Per-app energy can only be measured while Nightwatch is running. Turn on “Open at login” in Settings and it will fill in after the next night. Sleep, wake and “kept awake” details work regardless, because they come from macOS’s own log.

How accurate is the battery split between apps?

It’s an estimate: each app’s share of the energy Nightwatch measured, applied to the battery percentage lost. Processes owned by macOS itself can’t be measured without admin rights, so they aren’t included.

Does it work on a Mac without a battery?

Yes. On an iMac, Mac mini or Mac Studio you get the timeline, wake reasons, score and “kept awake” list; battery sections simply stay out of the way.

Will it change my sleep settings?

No. Nightwatch only reads. The one action it offers is quitting an app that’s keeping your Mac awake, and it asks you first.

macOS says it can’t verify the developer.

Nightwatch is distributed directly from this website. Here’s how to open it the first time.

Your Mac had a busy night.