The 10-Minute Laptop Check Before a Call or a Used Purchase

Ten minutes in a browser tab tells you whether a laptop is ready for an interview, a client call or a stream, and whether a used laptop or monitor is worth the price. Run the webcam and microphone tests, press every key, read the real screen resolution, flash full-screen colours to find bad pixels and copy a browser report. Then record a short dry run and play it back. The device tests work entirely on your machine: the camera and microphone streams play inside the page and aren't uploaded.

Two situations, one routine

On one afternoon you have a remote job interview at 15:00 and a laptop that has had two system updates since your last call. On another, you're in a café with a stranger selling a three-year-old laptop and a portable monitor. Both ask the same question: does this hardware do what it claims? Start the online stopwatch when you open the lid and press Lap after each step below, so you can see which check eats your time.

Step 1: Camera

Open the webcam test and click Start camera. You get the camera's name, the resolution it really delivers, a measured frame rate and the aspect ratio. A "1080p" laptop that shows 640 × 480 is using a different camera or isn't what the listing says. Below 15 fps the page warns you; dim light is the usual cause, so put a lamp in front of you, not behind. Choose a second camera from the list if there is one, and use Mirror view to frame yourself.

A black picture usually means Zoom, Teams or OBS still holds the camera, or access is blocked in the browser or system settings. Press Stop camera when you're done. Nothing was recorded.

Step 2: Microphone

In the microphone test, click Start test and talk normally. The meter labels the input from silent through a good level to too loud (clipping). Then press Record 5 seconds and listen. A mic can show a healthy level and still sound hollow or full of fan noise.

Echo cancellation and noise suppression are on by default, like most call apps. Untick the box to hear the raw microphone, which is the better guide when judging used hardware. The clip stays on your device.

Step 3: Keyboard

Click into the keyboard tester and run across every row. Keys turn green once they've worked, so any key that never changes colour needs another press. Check both Shift keys, the arrows, Enter, Backspace and the top row. Then hold several keys and read Most keys at once. Two or three is normal on cheap keyboards, but Shift plus a letter must work. The Fn key never reaches a web page, so don't count it against the machine.

Step 4: Screen resolution and refresh rate

The screen resolution checker shows the resolution the browser sees, the physical pixels behind it, the pixel ratio, the window size and an estimated refresh rate. A 2560 × 1600 panel at 200% scaling reports 1280 × 800, so compare the physical pixels with the spec sheet. A "144 Hz" monitor that measures 60 Hz may only need a setting or a better cable; ask the seller to show it at 144 Hz before you pay. Copy all details gives you a record to keep with the receipt.

Step 5: Dead and stuck pixels

Wipe the screen and start the dead pixel test. A dead pixel shows as a black dot on white; a stuck one as a coloured dot on black. Press Space or the right arrow for the next colour and Esc to leave. Check corners and edges, where nobody looks. A dot that moves when you wipe is dust.

Step 6: Browser report

Open what is my browser and press Copy full report. Before a call it shows whether your browser is out of date, a common reason meeting links misbehave. When buying, it confirms the operating system and graphics card the seller described. Support teams ask for exactly this text.

Step 7: Record a dry run

Hear yourself the way others will. Use the voice recorder to record a 30-second answer to "tell me about yourself", then play it back and save it as MP3 or WAV if you want to compare later. Listen for fan noise, room echo or a level that hits red.

If you'll share your screen, rehearse with the screen recorder. Tick Add my microphone, pick a window, wait for the three-second countdown and click through your demo. The playback reveals notifications you forgot to silence and text too small to read. It works in desktop browsers, not on most phones.

Finally, set an online timer for five minutes before the call. It beeps when time is up and shows the remaining time in the tab title.

Common mistakes

• Testing the camera in daylight for a call you'll take at night.
• Trusting the mic meter without playing the clip back.
• Reading the resolution with browser zoom at 125%. Press Ctrl/⌘ + 0 first.
• Skipping the full-screen colour pass on a used monitor.
• Closing the tab before downloading a recording. It's gone with the page.

Quick checklist

• Camera shows the expected resolution and at least 15 fps
• Mic clip sounds clear with processing on and off
• Every key turns green, including both Shifts and the arrows
• Physical pixels and refresh rate match the spec
• No dead or stuck pixels on any colour
• Browser report copied and browser up to date
• Dry run recorded and played back
• Five-minute timer running

More checks live in the device tests collection.