White Screen Test
A pure white full-screen fills your display so dark dead pixels, dust, smudges and shadows stand out instantly. Click the button to go fullscreen, and press Esc to exit.
Click the button to fill your entire screen with solid white. Click anywhere or press → to cycle colours, and Esc to exit.
What a white screen reveals
A solid white field is the fastest way to spot anything dark on your display:
- Dead pixels show as tiny black dots that never light up. Against white they are obvious; against most content they hide.
- Dust and smudges on the glass become visible, so you know what to clean before blaming the panel.
- Shadowing or clouding — uneven grey patches — can indicate pressure damage or a failing backlight zone.
Using your screen as a light
A full white screen doubles as a soft, even light source — handy as a tracing pad against a window, a quick fill light for a video call, or a torch in a dark drawer. Turn your brightness up for maximum output.
Cleaning check
Before deciding a mark is a defect, view it on white and wipe gently with a dry microfibre cloth. If it moves or disappears, it was dust. If it stays fixed and dark through cleaning, it is likely a dead pixel. Confirm with the full dead pixel test, which cycles white, black and every primary colour so you catch faults of any type.
White point and uniformity
On white you can also judge colour temperature: a healthy panel looks neutral, while a warm yellowish or cold bluish tint suggests your white point needs calibrating. Compare the centre with the corners — a large brightness or colour difference across the panel points to backlight non-uniformity.
Frequently Asked Questions
How does a white screen find dead pixels?
Dead pixels stay dark, so against a pure white background they appear as small black dots that are easy to see. Everyday content hides them, which is why a solid white field works best.
Is a dark spot on white always a dead pixel?
Not always. Dust or a smudge on the glass also looks dark. Wipe gently with a microfibre cloth first — if the spot moves or clears, it was dirt. A mark that stays fixed through cleaning is likely a dead pixel.
Can I use the white screen as a light source?
Yes. A full white screen at high brightness makes a soft, even light — useful as a tracing pad, a quick fill light for calls, or a torch. Raise your brightness for the most output.
Why does my white screen look yellow or blue?
That is your monitor's white point. A warm yellow or cold blue tint means the colour temperature is off and may need calibrating. Uneven tint across the panel suggests backlight non-uniformity.
How do I exit the full-screen white test?
Press Esc, or click and it cycles to the next colour. You can also switch directly to black, red, green or blue with the buttons before going fullscreen.
Should I run the full dead pixel test too?
Yes. White finds dark pixels, but stuck pixels show only on certain colours. The full dead pixel test cycles white, black and every primary so you catch every kind of fault.