How do I test for dead or stuck pixels?

Cycle through White, Black, Red, Green, and Blue in fullscreen. A dead pixel stays black on every colour; a stuck pixel shows the wrong colour on one or more of the tests. Turn on Auto-cycle and step back from the screen to catch defects more easily.

How do I check backlight bleed?

Pick Black, turn the brightness down a little, go fullscreen in a dark room. Panel edges that glow grey or blue-ish reveal backlight bleed. This is most visible on IPS and VA panels.

How do I use this as a Zoom or Google Meet fill light?

Pick Neutral white (or Warm for a softer look), set brightness to a comfortable level, and go fullscreen on the monitor that faces you. Sit roughly 40–80 cm from the screen so the light spreads evenly across your face. Tilt the monitor up slightly to lift shadows under the eyes.

Which colour temperature is best for video calls?

Neutral (≈4000 K) looks most natural on camera. Warm (2700 K) flatters skin tones but can look dim on-camera. Cool (6500 K) is the brightest and crispest but can wash out colours. Test all three with your webcam's auto white-balance locked.

Will my screen stay on while I'm testing?

Yes, the tool uses the Screen Wake Lock API to keep your display awake during long tests or video calls.

Everything happens locally in your browser. Nothing is uploaded. The tool works offline after the first load.

Does this work on phones and tablets?

Yes. The screen fills your device on any browser. For fullscreen without the browser chrome, use the Fullscreen button.

Can I pick a custom colour?

Yes. Use the custom colour picker next to the presets to set any hex value — useful for pairing with professional calibration targets.

How is this different from the Flashlight tool?

The Flashlight is built for emitting light in a useful colour or mode for reading, camping, or signalling. The White Screen is optimised for testing your display and for work-oriented lighting (video calls, photography, calibration). Different intents, different defaults.

White Screen & Monitor Test

Fullscreen white, black, red, green, blue, and grey. Find dead pixels, check backlight bleed, or use as a Zoom fill light.

Vos données ne quittent pas votre appareil

Test colours

Webcam whites

Brightness 100%

Auto-cycle Advance through colours automatically sec / colour

Press Start to fill the screen. Arrow keys cycle colours, C toggles auto-cycle, Esc exits fullscreen.

Common Use Cases

Dead & stuck pixel testCycle white → black → R → G → B. A permanent dark dot is a dead pixel; a coloured dot on the wrong test is stuck.

Backlight bleed checkBlack at low brightness in a dark room. Bright patches along edges reveal light leak, common on IPS/VA panels.

Uniformity check50 % grey shows tinting or banding that pure colours hide. Look for greenish, pinkish, or magenta corners.

Zoom / webcam fill lightNeutral white at comfortable brightness, fullscreen, 40–80 cm from your face. Cheap, instant softbox.

Photography fill or reflectorPure white, max brightness, as a reflector for product, macro, or still-life shots.

Before buying a used screenRun the whole sweep in ten seconds to spot defects that a casual "it turns on" check misses.

Keyboard

Space — start / exit fullscreen colour
← / → — previous / next colour
C — toggle auto-cycle
F — fullscreen the browser
Esc — exit

Outils associés

Flashlight Color Converter Pixel Ruler