White Screen Test: Find Dead Pixels, Dust and Uneven Brightness Online
Press F and this page floods your display with pure #FFFFFF — the brightest, cleanest field a screen can show. Against full white, dark pixels, dust, smudges and brightness clouds stand out instantly, which makes a white screen test the fastest way to inspect any display before cleaning it, buying it or complaining about it.
What a full white screen reveals
Press F for fullscreen, step back slightly, and let your eyes wander across the white field pixel by pixel. Any pixel that stays black or dark while everything around it glows is a dead pixel; a pixel pinned to a single color is a stuck pixel — both are far easier to see on white than on photos or desktop clutter. This is also the best moment to hunt for dust under the glass, fingerprints and smudges: they show up as soft gray shadows on white long before you notice them on normal content, so you can map every dirty spot before you start wiping.
Next, judge the light itself. A healthy panel is the same brightness corner to corner; blotchy clouds, a brighter hotspot in the middle or visibly dimmer corners point to uneven backlighting or aging LEDs. A slight warm or cool tint across the whole field is usually a color-temperature setting, not damage — verify it on the grayscale page. And if you have an IPS panel, note what you cannot see: the famous IPS glow lives in the blacks, not the whites, so a spotless white field says nothing about glow. You will need a black screen for that.
Practical uses and what to do about flaws
Beyond defect hunting, full white has quieter jobs. Photographers and video editors use it as a neutral, shadow-free light source for product shots or video calls, and many people simply keep it as a soft reading lamp. Before cleaning, run the white screen once: the dust, grease and sneeze marks that vanish against a busy desktop become a map of exactly where to wipe, so a single pass with a microfiber cloth finishes the job. It is also the standard check when unboxing a new monitor or phone, and the essential inspection before buying used — a five-minute white scan can save you from someone else’s dead pixels.
As for what you find: dead and stuck pixels on a new unit are grounds for exchange within most warranty windows, so document them promptly — the dead pixel page explains how to classify and report them. Uneven brightness and clouds are usually not fixable by settings; before blaming the panel, dim the screen a little and re-check, because at low brightness some backlights mask their own unevenness. Finally, put the result in context with the all-in-one screen test, which cycles white alongside every other solid color, black included.
Frequently Asked Questions
What is a white screen test used for?+
It fills the whole display with pure white so you can spot dead or dark pixels, locate dust and smudges before cleaning, and judge brightness uniformity and tint. It also works as a soft, neutral light source for photos or video calls.
How do I make my screen full white?+
Open this page and press F to enter fullscreen — the entire monitor turns #FFFFFF with no interface in the way. Press Esc or F again to leave.
What does a dead pixel look like on a white screen?+
A dead pixel appears as a tiny black dot that stays dark while the rest of the screen glows. A stuck pixel shows as a fixed red, green or blue point. Both are easiest to find against a solid white field.
Is IPS glow visible on a white screen?+
No. IPS glow brightens the corners of dark content, so it is invisible on white by definition. To evaluate glow, clouding or backlight bleed, switch to a black screen in a dark room.