Monitor Test
Fill any monitor, laptop, phone or TV screen with solid colors to check it for visible faults.
Used Laptop Check
Open this page on the laptop you are thinking of buying and work down the list. Each step links the test to run; mark it Pass, Problem or Skip and add a note. At the end, copy or print the report to take to the seller.
Your answers and notes stay in this browser tab, so you can open each test and come back. Nothing is uploaded, and closing the tab clears them.
Case and battery
Case and hinges
With the laptop off, look for cracks, dents and missing screws. Open and close the lid: the hinges should move evenly and hold the screen at any angle.
What to look forNot checked
Lies flat, lid closes flat
A bulging bottom, a raised touchpad or a lid that no longer closes flat can mean a swollen battery. That is a safety risk: walk away.
Not checked
Screen
Colors
Step through the colors full screen. Look for a tint on white, or bands of color.
Open the Monitor TestNot checked
Dead and stuck pixels
Turn on Auto cycle and scan the screen section by section. Note any dot that stays black, stays one color, or glows on black.
Open the Dead Pixel TestNot checked
Even brightness
On the gray fields, look for cloudy patches, pressure marks and dark corners.
Open the Screen Uniformity TestNot checked
Backlight bleed
Shade the screen and view the dark levels. Glow that shifts as you move your head is normal IPS glow; bright patches that stay put are bleed. Skip this on an OLED screen.
Open the Backlight Bleed TestNot checked
Picture while the lid moves
With a white color showing, move the lid slowly through its range. Flicker, lines or a picture that cuts out can point to a worn display cable.
Open the Monitor TestNot checked
Keyboard and touchpad
Every key
Press every key: each should light up, then turn back when released. Type a sentence to catch doubled or missing letters.
Open the Keyboard TestNot checked
Brightness, volume and backlight keys
These keys rarely reach a web page, so press them and watch the system respond.
Not checked
Touchpad
Move a finger across the whole pad, click, right-click and scroll with two fingers. The trail should be smooth and every count should rise.
Open the Mouse TestNot checked
Touch screen
Drag a finger over every cell to find spots that do not respond. Skip this if the screen is not a touch screen.
Open the Touch Screen TestNot checked
Speakers, microphone and webcam
Speakers
Play the left, then the right speaker, with your ear near each side. Turn it up for a moment and listen for rattles or crackling.
Open the Speaker TestNot checked
Microphone
Allow access and speak. The meter should rise when you talk and fall back when you stop.
Open the Microphone TestNot checked
Webcam
The picture should appear and be in focus. A black picture usually means a closed shutter, or a camera key or switch that is off.
Open the Webcam TestNot checked
Wi-Fi, ports and charger
Wi-Fi and Bluetooth
If this page loaded over Wi-Fi, Wi-Fi works; otherwise connect to your phone’s hotspot. Check that Bluetooth finds your phone.
Not checked
Ports and charging
Plug a USB drive or your phone into each port, and earbuds into the headphone jack. Plug in the charger and check that the battery shows it charging.
Not checked
Battery health and identity
Battery health
No web page can read battery wear. Read it in Windows or macOS with the steps in the guide.
How to check battery healthNot checked
Model, serial and accounts
Compare the model and serial number in the system with the listing and the label, and ask the seller to remove their accounts before you pay.
How to confirm the modelNot checked
Nothing checked yet: 18 checks to go.
Runs entirely in your browser. Test results, audio and video never leave your device.
How to run the used laptop check
- Open this page in the browser of the laptop you are checking, with the seller there, before you pay.
- Work down the list. Where a step has a link, open the test, run it, and come back with your browser’s Back button: your answers are still here.
- Mark each step Pass, Problem or Skip. Add a short note for anything wrong, such as “1 stuck pixel, top left”.
- Battery health and the serial number come from the operating system, not the browser. The links in those steps show where to find them.
- When every step has an answer, press Copy report or Print or save as PDF, and ask the seller about each problem before you pay.
How do I check a used laptop before buying it?
Work through a fixed list in front of the seller: look over the case and battery, then test the screen, keys, touchpad, speakers, microphone and webcam in the laptop’s own browser, and try the ports and charger. Mark each check as you go; this page keeps the results and turns them into a report.
What to do about a problem
- A bulging case or a lid that no longer closes flat can mean a swollen battery, which is a safety risk. Walk away.
- No software repairs a dead pixel, so count dead and stuck pixels and price them in.
- A private sale often has no returns, so ask about any key, port, speaker or camera that fails before you pay, and price in the repair.
- Do not pay until the seller has removed their accounts, including Find My on a Mac.
- The used laptop checklist explains each check, what counts as a defect, and how to read battery health and the serial number.
What the report shows
The report lists every step under its group with your answer, Pass, Problem, Skip or Not checked, and your note, followed by the counts. Copy report gives plain text you can paste into a message; Print or save as PDF prints just the steps and results, with the date and time.
It records what you marked while testing. It is your own record and a list of questions for the seller, not a certificate of the laptop’s condition.
What this test can detect
- Screen faults: a tint, uneven brightness, dead and stuck pixels, backlight bleed, and a picture that flickers as the lid moves.
- Keys, the touchpad and a touch screen that do not register.
- Speakers, a microphone or a webcam that does not work.
- Problems you find with Wi-Fi, the ports and charging, recorded with your notes.
- Whether you covered every check before paying, with a report to copy or print.
How it works
The page is a checklist: the tests run on their own pages, and you record each result here. Answers and notes are kept in this tab’s session storage, so they survive a visit to each test and a reload, and are cleared when the tab closes. Nothing is sent to a server.
Copy report puts a plain-text summary on the clipboard. Print or save as PDF prints only the steps and their results, with the date and time the report was made.
Limitations
- The results are what you mark. The page cannot tell whether each test was run, and each linked test sees only what a browser can.
- Battery wear, the model, the serial number and the storage size cannot be read by a web page, so those steps rely on the operating system.
- In a private window, or where the browser blocks storage, answers are kept only until the page reloads.
Frequently asked questions
Is the report proof of the laptop’s condition?
No. It records what you marked while testing, and a seller may see a fault differently. Use it as your own record and as a list of questions to ask before you pay.
Is anything I type here uploaded?
No. Answers and notes stay in this browser tab and are cleared when you close it. Copying and printing the report happen on your device. The privacy policy explains what the site collects.
Can I use it on a MacBook or a Chromebook?
Yes. The tests run in current browsers on Windows, macOS and ChromeOS. The guide’s battery and serial number steps cover Windows and Mac only.
How long does the used laptop check take?
About 15 minutes for all 18 steps, a little longer if you test every port or add notes. Run it before you pay, while the seller is there.