Mac Keeps Waking From Sleep? Here's Why

A MacBook that is warm in the bag, or an iMac that lights up at three in the morning, is not haunted. macOS records why it woke every single time, with a timestamp and a reason. Here is how to read that log and switch off whatever is responsible.

Read the wake log

# the last few wake events with their reasons
pmset -g log | grep -e "Wake from" | tail -20

# or the full sleep and wake history
pmset -g log | grep -E "Sleep|Wake" | tail -40

Each line ends with a reason code. The common ones:

• EC.LidOpen — you opened the lid. Not mysterious.
• RTC (Alarm) — a scheduled wake. Power Nap, Time Machine, or a scheduled task.
• Network / BT / USB — network traffic, a Bluetooth device, or something plugged in woke it.
• UserActivity Assertion — an app asked to wake the Mac.
• PWR Button — someone pressed it, including a bag pressing it.

The reason code tells you which of the sections below applies.

Stop network wakes

This is the most common cause on desktops and on any Mac that lives on Wi-Fi. Open System Settings → Battery → Options (on a desktop, Energy Saver) and set Wake for network access to Never, or Only on Power Adapter on a laptop.

# check the current setting: womp 1 means wake on network is on
pmset -g custom | grep womp

Also turn off Enable Power Nap on the same screen. Power Nap wakes the Mac periodically while it sleeps to check mail, sync notes and back up. That is the three-in-the-morning wake, and on a laptop in a bag it is also why the machine is warm and the battery is lower than you left it.

Stop Bluetooth wakes

A mouse on a desk that gets bumped, or a keyboard in the same bag as the laptop, will wake a Mac. Open System Settings → Bluetooth → Advanced and turn off Allow Bluetooth devices to wake this computer.

If that option is not where you expect it, the setting is per-device on some systems: disconnecting the device or turning Bluetooth off before sleeping proves whether it is the cause.

Check for scheduled wakes

# anything scheduled to wake or power on the Mac
pmset -g sched

Empty output means nothing is scheduled. If there are entries you did not create, look in System Settings → Battery → Schedule (or Energy Saver on a desktop) and clear them. Backup software and management tools sometimes add these.

Time Machine and the backup wake

Time Machine backs up hourly and will wake a sleeping Mac to do it if the destination is available. That is often the pattern behind a machine that wakes at the same minutes past each hour.

# when did backups run?
tmutil listbackups 2>/dev/null | tail -5

# is a backup running right now?
tmutil status

You do not want to turn Time Machine off. If the wakes are a problem, back up to a drive you plug in rather than a network destination, or set the backup to run only while the Mac is awake by connecting the drive during working hours.

The physical causes people miss

• The lid opening slightly in a bag. A MacBook wakes on the smallest lid movement. If the log says LidOpen, that is what happened.
• A connected charger or hub. Plugging in can wake a Mac, and a flaky cable can do it repeatedly.
• An external display waking. Some monitors send a signal on power cycling that wakes the Mac attached to them.
• Find My. Locating a Mac wakes it briefly. Rare, and it does show in the log.

If the wake log points at something you cannot identify, note the timestamp and check what runs at that time: backups, sync clients and updaters are all scheduled, and matching the clock to the schedule usually names the culprit.