White Screen

How to use a white screen

A pure white field turns on every red, green, and blue subpixel of the panel at the same time. Anything that is not white stands out against it, which makes it a quick first check for a new or used display, and a handy source of soft light.

1. 1

   Open it full screen. Browser toolbars around the field hide the edges and corners, which is where many faults sit.

2. 2

   Turn off color filters. Night mode, blue-light filters, and automatic color adjustment tint white toward yellow, which can look like a fault.

3. 3

   Clean the display first. Reflected light makes dust look like defective pixels. A speck you can wipe away is not a fault.

4. 4

   Look for dots that stay put. A dark or colored dot that does not move or wipe off may be a dead or stuck pixel. Confirm it with the Dead Pixel Test.

What a white screen can reveal

Beyond single pixels, look across the whole field. Darker corners or edges, patches that look slightly gray, cloudy areas, or a color tint that changes from one side to the other point to uneven backlighting or panel variation. A small amount of unevenness is normal on many displays, so compare what you see with the manufacturer's warranty terms before deciding a panel is faulty.

Light bleeding in from the edges is easier to judge on a dark field. Use the Black Screen for that check.

Cleaning and lighting

A white screen also makes smudges, fingerprints, and dust easy to spot while you clean. Switch the display off before wiping it, then turn it back on to check your work.

On a video call, a spare monitor or laptop showing a white screen works as a simple fill light. Place it in front of you, slightly above eye level, and lower its brightness if the light feels too harsh.

This screen's exact value has its own #FFFFFF color page, with its RGB and HSL values and its contrast against black and white.