How to Test a Used Laptop Before Buying
Meeting a seller from Facebook Marketplace, eBay or Swappa? Run this checklist on the laptop before you hand over any money. Every test runs free in your browser — no installs — so you can work through it in about 10 minutes while the seller is there.
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Confirm the specs match the listing
Check the CPU, GPU, RAM and OS actually match what the seller advertised — listings are sometimes copied from a higher-spec model. (Browsers can only read so much, so cross-check against the model number too.)
Open the system info tool → -
Check the battery health
See the charge level and learn how to read true battery health. Below 80% capacity means a replacement is due soon — use it to negotiate the price down.
Open the battery test → -
Inspect the screen for dead pixels
Run full-screen solid colours to catch dead or stuck pixels and backlight bleed. These are easy to miss on a busy desktop and a pain to live with.
Open the dead pixel test → -
Test colour and brightness
Check colour accuracy, gradients and brightness uniformity across the whole panel.
Open the screen test → -
Test every key
Press every key to confirm none are dead, sticky or repeating — a common fault on used laptops, and expensive to repair.
Open the keyboard test → -
Check the trackpad and mouse
Verify left/right clicks, scrolling and smooth pointer movement.
Open the mouse test → -
Test the webcam
Confirm the camera turns on and check the image quality and resolution.
Open the webcam test → -
Test the speakers and microphone
Play test tones for the left and right channels to catch a blown speaker or crackle, then check the microphone records cleanly.
Open the audio test → -
Check the graphics chip
Detect the graphics chip and run a quick visual artifact check. For a gaming laptop, follow up with a full stress test (FurMark or Unigine) before you commit.
Open the GPU test →
Red flags — negotiate hard or walk away
- Battery health below 80% with no price discount.
- Dead pixels or backlight bleed the seller never mentioned.
- Keys that do not register, or feel sticky.
- Specs that do not match the listing.
- The laptop only powers on while plugged in (a dead battery).
- Visual artifacts on screen during the GPU test, on a gaming laptop.
Frequently Asked Questions
How long does it take to test a used laptop?
About 10 minutes. Every test runs in the browser with no installs, so you can do it on the spot while meeting the seller.
What are the biggest red flags when buying a used laptop?
Battery health below 80% with no discount, dead pixels or backlight bleed the seller did not mention, keys that do not register, specs that do not match the listing, a laptop that only powers on while plugged in, and GPU artifacts on a gaming laptop. Any of these is grounds to negotiate hard or walk away.