Dead Pixel Test
Cycle fullscreen colors to find dead or stuck pixels on your display.
The screen cycles through black, white, red, green and blue. Look closely for pixels that stay black (dead) or keep showing the wrong color (stuck). Use arrow keys to change color and Esc to exit.
Your test runs locally in your browser. No device data is uploaded.
How to use the dead pixel test
Start the fullscreen test and step through each color with the arrow keys or the on-screen buttons. Inspect the screen closely, then press Esc to exit.
What this test checks
Each solid color fills the whole screen so any pixel that does not change stands out. A dead pixel stays black on every color; a stuck pixel keeps showing the same color.
Clean the screen first, since dust looks very similar to a defective pixel.
Small clusters of bright dots on a dark background are usually normal backlight bleed rather than pixel faults.
Common dead pixel problems
A handful of stuck pixels can sometimes recover over time. Manufacturers usually require a minimum number of faulty pixels before they accept a warranty claim.
Frequently asked questions
- What is the difference between a dead pixel and a stuck pixel?
- A dead pixel receives no power and stays black on every colour. A stuck pixel is powered but locked to one colour, so it shows as a bright red, green, blue or white dot against other backgrounds. Stuck pixels sometimes recover; dead ones do not.
- Why do I need to check several colours?
- Because a faulty subpixel is invisible against a background of its own colour. A pixel stuck on red disappears on a red screen and is obvious on a green one, so a single background will miss most faults.
- Can a stuck pixel be fixed?
- Occasionally. Rapidly cycling colours in that area, or gentle pressure through a soft cloth with the screen on, sometimes frees one. Neither reliably works, and pressing hard risks damaging the panel further — a truly dead pixel cannot be revived at all.
- How many dead pixels does a warranty cover?
- It varies by manufacturer and by panel grade. Many warranties require several faulty pixels before they accept a return, and some treat a bright stuck pixel more seriously than a dark dead one. Check the specific policy for your model.
- Does this work on a phone or tablet?
- Yes. Open the test on the device you want to check and go fullscreen. Turn the brightness up and inspect at a normal viewing distance, then look more closely at anything suspicious.