See what happened last night.
It reads the week macOS already remembers, so your first story is ready the moment it opens.
You closed the lid and walked away. Nightwatch tells you the rest of the story: when it really fell asleep, every time it stirred in the dark and why, which apps held it awake, and where the battery went.
Free · macOS 14+ · Apple silicon & Intel · No admin password · How to open it the first time
Nightwatch reads the power history macOS already keeps and turns it into a short, plain-English story of each 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 band coloured by state — asleep, dark wake, awake with the screen off, screen on — with the battery level drawn over 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.
Apps and services that blocked sleep while your screen was off, ranked by how long they held on.
While it runs, Nightwatch samples each app’s energy use and splits the overnight drain between them. Clearly labelled as an estimate.
See which apps are stopping sleep at this moment, and quit a misbehaving one — after you confirm.
Charge, cycle count, capacity versus new, temperature, and a chart of how much each night cost.
macOS forgets after about a week. Nightwatch keeps each night it reads, so you can look back over 7 or 30 nights.
Last night’s summary at a glance. The moon changes when something is keeping your Mac awake.
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.
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.
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.
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.
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.
No. Nightwatch only reads. The one action it offers is quitting an app that’s keeping your Mac awake, and it asks you first.
Nightwatch is distributed directly from this website. Here’s how to open it the first time.
It reads the week macOS already remembers, so your first story is ready the moment it opens.