How to check a used laptop before you buy it

A used laptop can be a great deal or an expensive mistake. Most problems — dead pixels, worn batteries, broken keys, a locked account — can be found in about ten minutes if you know where to look. Bring a USB stick and earphones, and run our full device check on the spot.

Problems to look out for

• Worn battery that lasts far less than advertised
• Dead or stuck pixels, pressure marks and backlight bleed on the screen
• Keys, touchpad buttons or ports that don’t work
• A device still linked to the seller’s Apple ID, Microsoft account or company management
• Overheating, loud fans or a slower processor than listed

The 10-minute checklist

1. Look it over first — Check the hinges, corners, screen surface and charging port. Ask for the original charger and make sure it charges.
2. Run the full device check — Open the full device check in a browser and go through every step. Save the report as a PDF — it is useful if you need to return the laptop.
3. Test the screen — Show solid white, black, red, green and blue full screen and look for dead pixels, bright spots and uneven light.
4. Press every key — Use the keyboard test to press every key, including the arrows, Fn row and number keys. Try the touchpad clicks and scrolling too.
5. Check the battery health — On Windows run powercfg /batteryreport; on a Mac open System Information → Power and look at the cycle count and condition. Under 80% of the design capacity means a replacement is coming.
6. Make sure it isn’t locked — Sign out of the seller’s accounts together, check Find My (Mac) or Find My Device (Windows), and confirm there is no company management profile.
7. Compare the specs — Check that the processor, memory and storage in the report and system settings match the listing.

Tip: Ask the seller to reset the laptop to factory settings in front of you after testing. A seller who refuses is a warning sign.

Should you walk away?

A worn battery or a single dead pixel can be a reason to negotiate. A locked account, a cracked hinge, a screen with many dead pixels or a laptop that won’t charge are reasons to walk away.