Can a Mac play a sound when the charger is unplugged?

Yes — macOS notifies software when power state changes, so an app or script can react instantly to the cable being pulled. The catch is that a useful theft alarm needs much more than the notification: forced maximum volume a thief can't turn down, a blocked quit shortcut, and coverage of the other grab moves like closing the lid.

Why is the charger the classic theft trigger?

Because it's the one physical connection between a laptop on a café table and the world. A grab-and-run starts by yanking the cable — it's faster than closing the lid and quieter than anything else. That's why unplug detection is the oldest laptop alarm trick; it's necessary, just not sufficient.

The first move of every laptop grab is the charger pull.

By Peter Theill · August 2026 · 4 min read

Watch security footage of café laptop thefts (I have, it's a strange hobby) and the choreography is always the same: hand on the lid, yank the cable, tuck, walk. The cable comes out first. Which makes it a beautiful tripwire.

Yes, your Mac can notice

macOS tells running software the moment power state changes — that's how the battery icon updates. So "play a sound when unplugged" is genuinely easy, and the internet is full of DIY versions: a shell script polling pmset -g batt, an Automator loop, a Shortcuts hack. If you enjoy building things, it's a fun afternoon.

Where the DIY version dies

I know because I started there. The script fires, your Mac plays a bell... and then reality arrives:

The thief owns the volume keys. Your alert plays at whatever volume the Mac happens to be at — which in a café is "polite" or "muted". One tap of F10 and your alarm is a memory. A real alarm has to force volume to 100 % and keep forcing it, every second, unmuted.
The charger is one trigger of five. Plenty of grabs never touch the cable — you weren't plugged in, or they close the lid first. Touch, lid, movement and sleep all need the same tripwire. (The full trigger checklist is in the MacBook alarm article.)
Scripts are quittable. Terminal is right there. A real alarm blocks ⌘Q and ⌘-Tab and refuses to close.
A bell isn't embarrassing. Ding! sounds like a Slack message. What stops a thief mid-café is a red screen, a siren, and a voice announcing "HELP! I'm being kidnapped!" — something that makes every head in the room turn toward whoever's holding it.
You need a graceful off-switch. If disarming your own alarm is fumbling for a terminal window, you'll stop arming it within a week. It should be a 4-digit PIN typed blind, and then the volume goes back to exactly where it was.

Unplug detection is the tripwire. The alarm is everything that happens after the trip.

The ready-made version

All of the above is precisely why Don't Touch exists. One click on Arm and the screen fades to a calm aurora. Pull the charger — or touch a key, close the lid, or move the laptop — and it goes red, sirens at forced full volume, and talks back until the PIN is typed. It even handles the nasty edge case: close the lid on battery and the Mac must sleep, so it wakes up screaming instead.

Unplug alarm, plus the other four tripwires

Native Mac app, ~0.5 MB, no account, no cloud, never talks to the internet. $5 once, all your Macs, macOS 13+.

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