Buy a used Mac without the guesswork.
Mac Check inspects a second-hand MacBook in about ten seconds, then walks you through the tests only you can do. Know about locks, hidden faults and worn parts before you pay.
Ownership locks
Battery and charger
Everything a seller won't mention.
More than 25 checks run automatically. Each result explains, in plain English, what it means and what to do about it. Nothing on the Mac is changed.
Locks that make a Mac worthless
Activation Lock, company or school ownership, and remote management can all lock the Mac after you've paid, even after a full erase. Mac Check finds them first.
Battery health
Real capacity in mAh against the original, charge cycles, and whether the charger is genuine.
SSD wear
Life used, data written, hours powered on and errors, read straight from the drive.
Tampering
Disabled security features, hidden accounts, remote login, and remote-control or tracking tools left behind.
Crash history and parts
Whole-system crashes that point to failing hardware, plus Wi-Fi reach, Bluetooth, camera, microphone and Touch ID.
Then test it by hand.
Some faults only show up when you look, listen and touch. The app guides each one.
Screen and keyboard
Full-screen colours reveal dead pixels. A keyboard map lights up every key you press.
About 2 minutesSpeakers and trackpad
Left and right tones, a bass sweep for rattles, and a Force Touch pressure meter.
About 1 minuteStress test
Full power on every core to expose overheating, a weak fan or a board that crashes under load.
3 minutesPorts and Bluetooth
Each USB-C port lights up when it detects a device. A scan proves Bluetooth works.
About 2 minutesUsing it at the seller's.
Bring it on a USB stick
Copy the DMG before you go, so you don't need the seller's Wi-Fi to get started.
Check before anything is erased
Crash history and leftover software disappear after an erase, so look first.
Do the hands-on tests
Screen, keys, speakers, trackpad, stress test and ports take about ten minutes.
Watch the erase, then pay
Setup must not ask for the seller's Apple Account or show a Remote Management screen.
Installing takes a minute.
Mac Check is free and isn't sold through Apple, so macOS asks you to confirm it once.
Drag it into Applications
Open the DMG and drag Mac Check onto the Applications folder.
Open it and click Done
macOS shows “Apple could not verify Mac Check”. That's expected.
Click Open Anyway
In System Settings › Privacy & Security, scroll down and click Open Anyway. It opens normally from then on.
Copying the DMG from a USB stick formatted as ExFAT or FAT32 usually skips this prompt, which is handy on a seller's Mac.
Questions.
Is it safe to run on someone else's Mac?
Yes. It only reads information and changes nothing. The optional admin checks ask for the password through macOS's own dialog, so the seller types it. All the code is open on GitHub.
Which Macs does it work on?
Apple Silicon Macs (M1 and later) running macOS 12 Monterey or newer. Intel Macs aren't supported.
Does it need the internet?
No, except for one admin check that asks Apple whether an organisation owns the serial number, and Apple's warranty page.
Can it check the warranty automatically?
Apple doesn't offer a public way to do that, and its coverage page uses a CAPTCHA. Mac Check copies the serial number and opens the page, so you only paste it.
Does a clean report guarantee the Mac is perfect?
No tool can promise that. Mac Check catches the common deal-breakers and hidden faults, and Apple Diagnostics (hold the power button, then press ⌘D) covers the rest of the hardware.