Monitor test online — dead pixel check
Online monitor test for dead and stuck pixels: fullscreen black, white and color fills plus a banding gradient. Find screen defects in a minute.
Let's check the screen for dead pixels
The test opens fullscreen and shows solid colors. Inspect the screen carefully on each one: defective pixels show up as dots that don't change color.
Controls: click or → for the next color, Esc to exit.
How to check a monitor for dead pixels
A dead pixel is a dot on the screen that doesn't display color: either it's always black (a dead subpixel) or stuck on one color. Such defects are only visible on a solid background, so the test fills the whole screen with black, white, red, green and blue — each color reveals a different defect type.
How to check: open the test fullscreen, remove glare, and slowly scan the surface zone by zone on every color. On black, look for glowing dots — those are stuck pixels; on white and colors look for dark ones — those are dead. The gradient at the end reveals banding: stepped transitions where they should be smooth.
A couple of dead pixels on a large monitor is common: the ISO 13406-2 standard allows several defective subpixels per million for class II panels. A new monitor with a noticeable number of defects can often be exchanged — run the test right after purchase while the return window is open.
What the monitor test shows
All key colors
Black, white and RGB reveal different defects: dead, stuck and hot pixels.
Fullscreen mode
The fill opens fullscreen with no browser chrome — every dot of the matrix is visible.
Anti-banding gradient
A smooth black-to-white sweep exposes banding and color-depth issues.
FAQ
What's the difference between dead and stuck pixels?
A dead pixel is always black — it doesn't light up on any color. A stuck pixel constantly glows one color (red, green, blue or white) and stands out on black. Stuck pixels sometimes recover over time; dead ones don't.
Which color reveals defects best?
Look for dead pixels on white and saturated colors (red, green, blue) — they appear as dark dots. Look for stuck ones on black, where they glow. That's why the test cycles through all the basic fills.
Is a dead pixel covered by warranty?
It depends on the manufacturer and panel class. ISO 13406-2 allows a few defects per million subpixels for class II, so a single dot may formally not qualify. Still, most stores exchange a defective monitor within the first 14 days — test right after purchase.
Can a stuck pixel be fixed?
Sometimes rapidly cycling color videos (pixel refreshers) for 10–60 minutes help, or gently massaging the spot through a soft cloth. No guarantees, and dead (black) pixels can't be fixed this way — only a matrix replacement helps.
Why is there a gradient in the test?
The gradient reveals color banding: if you see distinct steps instead of a smooth black-to-white sweep, the monitor handles brightness gradations coarsely. That's a panel or settings trait, not a pixel defect — useful to know for photo and video work.