Fill your screen with pure white — a soft light for video calls, a lamp in a pinch, or a quick check for dust and stuck pixels. Slide the lightness down when full white is too much.
For the strongest light, turn your screen brightness all the way up.
A screen showing pure white is simply a big, soft light — and that turns out to be useful far beyond testing. Here is what people use this page for.
On a video call, the light in the room often comes from behind or above you, leaving your face in shadow. Open this page, make the screen white, turn the brightness up and face it — the screen becomes a soft panel light that evens out your face without the harsh glare of a desk lamp.
Photographers use big white surfaces to bounce soft light into shadows. A laptop or tablet showing this page works the same way for close-up shots and small objects.
A white screen at full brightness makes a surprisingly good reading or bedside light — soft, even and instantly adjustable. Slide the lightness down if bright white feels too harsh late in the evening.
Specks of dust, smudges and stuck dots all hide on a busy desktop but stand out instantly on a plain white background. Go fullscreen, wipe the screen, and anything that stays put is on the panel itself — a colored dot that never moves may be a stuck pixel worth testing properly.
A full white screen makes uneven brightness easy to see: darker corners, a yellowish patch, or a stripe that looks dimmer than the rest. If everything looks smooth and even, your backlight is doing its job.