SleepPeek

The question it answers: why isn’t my Mac sleeping?

What you see

• A headline from macOS’s own counters: something is keeping the Mac awake, only the display is held on, you are active, or nothing is blocking sleep.
• Each blocker: the process, its PID, the assertion type, its name and how long it has been held.
• macOS’s own “sleep prevented by…” summary, quoted as reported, and your display and system sleep timers.
• Other assertions (user activity, USB and network wake) collapsed below.

Fact versus inference

Every statement is labelled:

• Reported by macOS: read directly from the system.
• Likely (inference): a common explanation from a small, conservative list. For example, a power-management daemon holding the display on is normal while the display is on. Unknown holders get facts only, never a guess.

How to use it

1. Open SleepPeek. It refreshes every few seconds while the screen is open.
2. Find the blocker: a video call, a download, a backup or a development tool is the usual suspect. Open ProcessPeek to inspect it.
3. Press Load history to see recent sleep, wake and background-wake events with the reason exactly as macOS logged it, and the latest scheduled wake requests.

Good to know

• Load history is slower. macOS can take up to a minute to produce its power log, so it runs only when you ask, and stops if you leave the screen.
• SleepPeek only reads. It never changes a power setting.
• Wake reasons are shown as macOS wrote them and are never reinterpreted.

Privacy

Read-only; nothing is sent anywhere. See Why won’t my Mac go to sleep?.