Device tests

Which device test do you need?

Screens

• Buying or receiving a screen? Start with the screen test: its quick check covers dead pixels, backlight bleed and uniformity in about two minutes.
• Looking for faulty pixels only? The dead pixel test shows nine full-screen colours, lets you mark each defect, and compares the count with the usual warranty tolerance.
• Colours look wrong, washed out or tinted? The screen colour test checks tint, banding, detail in dark and bright tones, gamma and wide colours, one question at a time.
• Is your 144 Hz monitor really running at 144 Hz? The refresh rate test measures the rate in use and says when the browser itself limits it.
• Blurry picture, or a resolution you do not recognise? The screen resolution test gives the real pixel count, explains scaling, and checks that the screen runs at its native resolution.

Input devices

• Keys that do not respond or type twice? The keyboard test shows every key, detects chatter and checks how many keys work at once.
• A mouse that double clicks on its own, or a jumpy wheel? The mouse test counts unwanted double clicks per button, checks the wheel and estimates the polling rate.
• How fast can you click? The click speed test measures your clicks per second, your fastest second and your rhythm, and keeps your personal bests.
• A game controller that drifts? The gamepad test checks every button and trigger, measures stick drift and tells you the dead zone to set in your games.
• A phone or tablet that ignores some touches? The touch screen test finds dead zones and checks how many fingers are detected at once.
• A screen that no longer rotates, or a compass that points the wrong way? The sensor test checks the accelerometer, the gyroscope and the compass, with a bubble level.

Sound, video and vibration

• No sound, sound on one side only, or crackling? The speaker test checks the left and right channels, plays white noise and sweeps the whole frequency range.
• How deep does your bass go, and how high can you hear? The audio frequency test is a precise tone generator with a sweep, WAV files and two guided checks.
• Others cannot hear you on calls? The microphone test shows your live level, checks your voice against the background noise, and records a clip you can play back.
• A camera that shows nothing, or a dark picture? The webcam test shows the picture with its real resolution and frame rate, and judges the lighting.
• A phone that no longer vibrates, or buzzes when it does? The vibration test checks the strength, the short taps and the steadiness of the motor in 30 seconds.

How these tests work

Every device test runs in your browser, using the features browsers already offer: full-screen display, keyboard, mouse, touch and controller events, sound, vibration, motion sensors, and access to the microphone and camera. Nothing is installed and nothing is uploaded. When a test needs a permission, such as the microphone or the camera, your browser asks you first, and the test only starts when you press its button.

Some things cannot be checked from a web page. The Fn key of a laptop never reaches the browser, a screen’s brightness or colour accuracy needs a hardware measuring device, and a controller’s input lag cannot be measured by a page. Each test explains its own limits next to its result, and our methodology explains the general ones.

Tips for reliable results

• Test in good conditions: a clean screen, a quiet room for audio, and power saving turned off.
• Close other programs that use the device you are testing, such as a video call that holds the camera or the microphone.
• Repeat a test before concluding that something is broken. A problem that appears every time is a real one; one that comes and goes may be a loose cable or a setting.
• Save your results. Each test keeps a history in your browser and gives you a link, so you can compare a device over time, before and after a repair, or send the result to a seller.