Think someone is using your laptop while you're out? What to do on a Mac

MacUpdated

You come home, or wake up, and the Mac isn't quite how you left it: the lid open, a different window in front, a browser tab you don't remember. It might be nothing, and it might be someone at home borrowing it. Either way, a few settings on a Mac make it much harder for anyone else to use it, and one app can show you who unlocks it.

Quick answer

Check for signs of use first, then change your Mac login password, remove any fingerprint you don't recognise from Touch ID, give anyone who needs a Mac their own user account, and set the Mac to ask for your password soon after the display turns off. To see who unlocks it from now on, an app such as Failshot can photograph whoever unlocks it while the app is on. If you don't feel safe at home, read 'What if I don't feel safe at home?' below before you change anything.

How can I tell if someone used my Mac while I was out?

Start with what the Mac itself records, and compare the time you were out with your normal use. If Screen Time was already turned on, it can show how often the Mac was woken (choose this Mac in the Device menu, not All Devices). Recent Items lists apps and documents opened lately, and your Apple Account lists the devices signed in with it, so you can spot one you don't know. Screen Time and Recent Items can show whether the Mac was used. None of these shows who.

We've written these checks up step by step:

Try to keep an open mind while you look. A sign of use on its own doesn't tell you who or why. The steps below are worth doing whatever you find.

Should I change my Mac password?

Yes, if anyone else might know it. Someone who knows your login password can unlock your Mac as you, so changing it is the simplest step.

  1. Choose Apple menu > System Settings, then click Users & Groups in the sidebar. You may need to scroll down.
  2. Click the Info button next to your user name.
  3. Click Change.
  4. Enter your current password in Old Password, then your new password in New Password and again in Verify.
  5. Leave the hint blank if someone at home could guess your password from it, then click Change Password. Apple says the hint appears after three wrong passwords in a row, or when someone clicks the question mark in the login window.

While you're in System Settings, check Touch ID too. Apple says you can add up to three fingerprints to your user account, and the list shows each one.

  1. Choose Apple menu > System Settings, then click Touch ID & Password in the sidebar.
  2. If there are more fingerprints than you added, delete the extra ones, or delete them all and add yours again. To delete one, click it, enter your password, click Unlock, then click Delete.

Can someone else have their own account on my Mac?

Yes, and if they genuinely need to use it, this is the fairest fix for both of you. Apple says that when each person has their own account, each can personalise settings and options without affecting the others. A standard user can install apps and change their own settings, but can't add users or change other users' settings.

  1. Choose Apple menu > System Settings, then click Users & Groups in the sidebar.
  2. Click Add User below the list of users. You may be asked for your password.
  3. Click the New User pop-up menu and choose Standard.
  4. Enter a full name. An account name is created for you. You can change it now, but not later.
  5. Enter a password, then enter it again to verify, and click Create User.

For someone who only needs the Mac now and then, Apple also describes a Guest User account, which lets people log in without access to other users' files or settings. It's in Users & Groups too.

How do I stop my Mac being used when I leave it?

Make it lock quickly and ask for your password every time. Apple's Lock Screen settings let you choose how soon after the screen saver begins or the display turns off the Mac asks for your password. Apple also warns that automatic login allows anyone to access your Mac simply by restarting it.

  1. Choose Apple menu > System Settings, then click Lock Screen in the sidebar.
  2. Set "Require password after screen saver begins or display is turned off" to a short time.
  3. In System Settings > Users & Groups, set "Automatically log in as" to Off.

For every way to lock the screen before you walk away, including the keyboard shortcut and hot corners, see how to lock your Mac screen.

What if I don't feel safe at home?

If the person using your laptop is a partner or someone you live with, and it's part of a pattern of being checked on, controlled or frightened, you don't have to work this out alone. In the UK, the National Domestic Abuse Helpline, run by Refuge, is free, confidential and open 24 hours a day on 0808 2000 247, and at nationaldahelpline.org.uk. You can also contact your local police. In an emergency, call 999.

Please don't go through their devices to find out. The helpline can talk through what feels safe for you, including any changes you're thinking of making.

Refuge's tech safety guide says some changes you make to your security might alert an abuser, and they might escalate their abusive behaviour. That includes changing your password, or adding an app like Failshot, which tells whoever unlocks your Mac that they were photographed. If you think someone checks this Mac, contact the helpline from a device they can't get to.

Where Failshot fits

The steps above make it harder to use your Mac. They don't show who unlocked it. Failshot is a Mac app, out now as a download from failshot.app, for macOS 14 or later, that photographs whoever unlocks your Mac while it's on. It's not a way to check up on anyone: it's for your own Mac, and it tells whoever unlocks it that it's there.

  • With Failshot on, it photographs whoever unlocks your Mac, then records a 5-second video. Video is on by default and can be switched off. Sound is off unless you turn it on, and the app warns you that recording someone's voice without their permission is against the law in some places.
  • Whoever unlocks sees Failshot's window saying the unlock was photographed, and when a video is recording. With the Mac's built-in camera, the green light comes on.
  • In Unlocks, "That was me" deletes an unlock's photos from your Mac, and from your web vault if you use it. In the encrypted web vault, you can also mark each unlock "This was me", "Not me" or "Not sure".
  • Email alerts are optional, and off until you turn them on. With them on and signed in to a Failshot account, an alert with the photo, the time and, when it's ready in time, the video follows shortly after an unlock you don't confirm as yours. Unlocks you confirm as yours don't send one. With alerts on, Failshot also emails you about a wrong Failshot PIN or answer, or its camera access being switched off while it's on.
  • Photos are kept on your Mac. They leave it only in email alerts and the encrypted web vault, if you turn those on, and, if you join your organisation with its invite code, encrypted for its security team too.
  • Switching Failshot off, or quitting it from its menu, takes Touch ID or your Failshot PIN and answer, never your Mac password. So someone who knows your Mac password can't switch it off in Failshot with that, and a wrong Failshot PIN or answer takes another photo. Like any Mac app, it can still be force-quit, and it closes when the Mac restarts, shuts down or logs out.

Failshot is free to download, but turning it on needs Failshot Pro, a paid subscription, and there's no free trial. Failshot Pro is £3.99 a month or £23.99 a year, VAT included, for as long as you stay subscribed, if you subscribe by 31 October 2026. From 1 November 2026 new subscriptions are £5.99 a month or £35.99 a year.

What it doesn't do: it doesn't photograph a wrong password at the macOS login or lock screen. It doesn't photograph the first login after a restart or a log out. Logging out, restarting or shutting down closes Failshot without asking for Touch ID or your Failshot PIN, and unless you've set it to start at login, it stays off until you open it again. Failshot runs in your own user account, so it doesn't photograph someone who logs in to their own account or the Guest User account. It can't find a lost Mac on demand: location, if you turn it on, is noted only at an unlock. It has no remote lock or wipe. iPhone, Android and Windows versions are coming soon.

Questions people also ask

How do I know if someone used my laptop while I was out?

Compare the time you were out with your normal use: if Screen Time was already on, its pickups, which Apple describes as the number of times you wake your device, and Apple menu > Recent Items. These show the Mac was used, not who used it. A photo taken when the Mac is unlocked can show who it was.

Someone used my laptop while I was asleep. What should I do first?

If you feel unsafe at home, talk to the National Domestic Abuse Helpline on 0808 2000 247 before you change anything, from a device the other person can't get to. Otherwise, change your Mac login password, check Touch ID & Password for fingerprints you didn't add, and set the Mac to ask for your password soon after the display turns off.

Can I stop someone using my Mac without falling out with them?

If they need a computer now and then, give them their own standard account or turn on the Guest User account. Apple says a guest can log in without access to other users' files or settings, so your own account stays yours.

Will Failshot tell the person they were photographed?

Yes. Whoever unlocks sees Failshot's window saying the unlock was photographed, and when a video is recording. With the Mac's built-in camera, the green light comes on too. Use it only on your own Mac.

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