How to make your MacBook sound an alarm if someone touches it

Does macOS have an alarm like this built in?

No. macOS can lock the screen and ask for a password, and Find My can play a sound on a Mac when you trigger it remotely. Neither one reacts on its own when somebody picks up your MacBook. If you want the Mac itself to sound an alarm the moment it's disturbed, you need an app that watches for that.

That's what MacGuard does. You arm it before you step away, and it sounds a loud siren if the MacBook is moved, its lid is closed or opened, it's woken, or someone starts using the keyboard or trackpad.

How MacGuard knows someone touched your Mac

Apple silicon MacBooks have motion and lid-angle sensors. MacGuard reads them through a small helper that you approve once in macOS, and combines them with input and power events:

• Movement. The accelerometer and gyroscope notice the Mac being lifted, slid, or carried. You can pick low, normal, or high sensitivity.
• Input. A key press, trackpad or mouse movement, click, or scroll. MacGuard registers that input happened, never what was typed.
• Lid. Someone starts to close the lid.
• Wake. The Mac is woken from sleep, or something tries to put it to sleep while it's guarding your desk.

Sensor channels differ between MacBook models. After you approve the helper, MacGuard shows which of these protections your Mac supports and switches off any it can't use.

Set up the alarm

1. Download MacGuard (free), open the DMG, and move MacGuard to Applications.
2. Open MacGuard. It lives in the menu bar at the top of the screen.
3. In MacGuard Settings → Motion Helper, choose Enable Motion Helper… and approve it in macOS. If asked, allow MacGuard in System Settings → General → Login Items.
4. Pick a protection mode and the triggers you want.
5. Click Arm & Lock. After a short countdown the Mac locks and the alarm is armed.

To turn it off, use Touch ID or your Mac password. Nobody else can silence it from the menu bar.

Which mode to use where

Desk · Screen Open

For a Mac left open on a table: a café, a library, a coworking desk, a meeting room while you step out. Movement, input, lid, and wake triggers all work here, and you choose which ones are on. In a busy café with a wobbly table, lower sensitivity cuts down on false alarms. On a quiet desk, normal or high catches a gentler lift.

Closed · Sleep Guard

For a Mac you've closed and left behind, like on a hotel desk or in a bag. Arm it, and you get a grace period to close the lid. The next time anyone opens or wakes the Mac, the alarm sounds.

Test it without startling the room

Try MacGuard on the Mac and in the places you'll actually use it before you rely on it. While disarmed, you can turn off Play local siren when alarm triggers for silent testing. Triggers still fire and the alarm state still shows, but no sound plays. An orange warning stays visible until you turn the siren back on.

If you've paired an iPhone, Send Test Alert in the menu-bar panel checks that alerts reach your phone.

Alerts and photos on your iPhone

The alarm works on its own. If you also want to know about it when you're out of earshot, the MacGuard companion for iPhone and iPad gets an alert when the alarm goes off and the Mac is online.

With Camera Evidence on, the Mac records up to about 20 seconds of video that stays on the Mac, and can make up to three photos available privately to your paired iPhone. MacGuard checks only whether a face is in view. It doesn't identify anyone.

What an alarm can and can't do

• It deters and alerts. It can't stop someone who is determined to run off with the Mac.
• It isn't a tracker. Keep Find My turned on so you can locate, lock, or erase a Mac that's gone.
• No app can keep sounding after a Mac is forcibly powered off.

Our MacBook anti-theft checklist covers the other settings worth turning on.

Get MacGuard

Free for Apple silicon MacBooks with macOS 14 or later.