TenSecondCheck

Check a used device before you buy

Answer a few quick checks on the device you are buying. At the end you get a report you can show the seller or keep for yourself.

Runs in your browser only

What are you checking?

We guessed from your browser. Change it if we got it wrong.

Check these by hand

A browser cannot reach any of this, so look at it yourself before you pay. It is the part that costs the most to get wrong.

Battery health

  • Windows: open Command Prompt and run powercfg /batteryreport. It saves an HTML file that compares the design capacity with what the battery holds now.
  • macOS: System Settings → Battery → Battery Health.
  • iPhone: Settings → Battery → Battery Health & Charging shows the maximum capacity as a percentage.
  • Android: there is no standard place for this. Look in the phone maker’s own device care or diagnostics app, and watch how fast the charge drops while you are testing.

Charging and sockets

  • Plug the charger in and confirm the device really starts charging, not just lights up.
  • Wiggle the cable gently where it meets the device — the charge should not cut out.
  • Try every USB port, the card slot and the headphone socket with something you brought with you.

Physical buttons and hinges

  • Power, volume and lock buttons should click cleanly, without feeling mushy or needing a hard press.
  • On a laptop, open and close the lid: the hinge should hold any angle and closing it should put the machine to sleep.
  • Check the fingerprint reader and, on a phone, the silent switch if it has one.

Unlinked from the previous owner

  • This is the one that turns a cheap phone into a brick. Ask the seller to reset the device in front of you and set it up from scratch.
  • iPhone or iPad: the device must be signed out of the previous owner’s Apple Account and Find My must be off. If it asks for someone else’s password after a reset, you cannot use it.
  • Android: the previous owner’s Google account must be removed before the factory reset, otherwise the phone asks for that account afterwards.

Before you meet the seller

A used device is easiest to judge when you arrive prepared. Bring a charger or a USB‑C cable, wired headphones, and a USB stick if you are buying a laptop. For a phone, bring your SIM card so you can make a test call.

Agree to meet somewhere with power and decent light, and plan at least fifteen minutes. A seller who is in a hurry to finish in two minutes is making the check harder on purpose.

Look up the exact model before you go. Know how much storage and memory it should have, and which colour and year match the listing.

How to use the check on this page

Open this page on the device you are buying, not on your own phone. The check picks laptop, phone or tablet from the browser; change it if the guess is wrong, then press Start the check.

Each step explains what to look at and gives you a small test: full‑screen colours, a keyboard map, the camera, the microphone level and left and right speakers. Mark every step as Works or There is a problem, and add a short note where something looks off.

At the end you get a report. Copy its link, show the QR code to the seller, or save it as a PDF.

Checking a used laptop

  • Screen. On black, look for bright dots; on white, for dark dots, stains and pressure marks. Uneven light along the edges is common on older panels, but a bright patch in the middle is not.
  • Keyboard and touchpad. Press every key, including the function row and the arrows. A dead key, or one that types twice, is expensive to fix on a laptop.
  • Camera, microphone and speakers. Check that the picture is sharp, that your voice moves the level meter, and that both speakers play equally loud without rattling.
  • Ports. Plug your USB stick and headphones into every socket you can reach.
  • Heat and noise. Play a video for a few minutes. The fan may speed up, but it should not rattle, and the case should not get too hot to hold.
  • Battery. On Windows, run powercfg /batteryreport and compare the design capacity with the full charge capacity. On a Mac, see System Settings → Battery.
  • Specifications. Compare the system information screen with the listing. The My device page gives a quick first look.

Restart the laptop once. If it asks for a firmware password before the system starts, or the Mac shows Activation Lock, do not buy it until the seller removes it.

Checking a used phone

  • Screen and touch. Drag a finger across every part of the touch grid. On OLED screens, look at a flat grey colour for faint shapes of old apps — that is burn‑in, and it does not go away.
  • Both cameras. Check front and back, and make sure the picture focuses.
  • Calls and sound. Make a short call with your SIM card, then test the speaker and microphone in the check.
  • Battery. On an iPhone, Settings → Battery shows the maximum capacity. On Android, there is no single standard place, so watch how fast the charge drops while you test.
  • Unlock and fingerprint or face. Add your own fingerprint or face and make sure it works.
  • IMEI. Dial *#06# and compare the number with the box and the settings screen.
  • Signs of repair. Look at the gaps between the screen and the frame, and at the screws next to the charging port. Uneven gaps or scratched screws mean the phone has been opened, so ask the seller what was replaced.

Red flags

Walk away if the seller will not let you test, if the device is still signed in to someone else’s Apple or Google account, if the IMEI does not match the box, or if the price is far below similar listings. Ask for a reset to factory settings in front of you, and set the device up as new before you pay.

After you buy

Reset the device once more at home and sign in with your own accounts. Keep the report link: if a problem you both saw was marked in it, you have a written record of the device’s condition on the day you bought it. If a fault the seller did not mention shows up in the first days, the report makes that conversation calmer.

For a closer look, use the full tests: screen, keyboard, microphone, camera and speakers.

Questions and answers

Can I run the check on my own phone instead of the device I am buying?
No. Every test measures the device the page is open on. Open this page in the browser of the laptop or phone you are about to buy, and hand it back to the seller only after the report is ready.
Is the report proof that the device is in good condition?
It is a record of what you saw at that moment, written on the device itself. It does not replace a warranty or a repair shop's diagnosis, and a seller could hide a fault that only appears after an hour of use. Treat it as a checklist, not a certificate.
The browser will not give access to the camera or microphone. What now?
Allow access in the prompt, or in the site settings next to the address bar. If the seller's browser has everything blocked, skip that step and test the camera in the system's own camera app instead.
How long does the whole check take?
The guided steps take two to three minutes. Add another five to ten for the manual list — battery health, charging, buttons and accounts — which is where the expensive surprises hide.