Dead Pixel Test
Cycle through 6 solid colors fullscreen to find dead, stuck, or hot pixels. Takes about 60 seconds.
← → navigate · Space auto-cycle · Esc exit
How to use the dead pixel test
- 1
Click Start Test to open the fullscreen color display.
- 2
Examine your screen carefully at each color. Look for tiny dots that are a different color or remain black.
- 3
Use the arrow keys or on-screen buttons to move between colors, or press Space to auto-cycle.
- 4
Cycle through all 6 colors: black, white, red, green, blue, and yellow.
- 5
Press Esc or the ✕ button to exit when done.
Why we test each color
Black
Reveals hot pixels — pixels that glow when they should be off. Also shows backlight bleed on LCD monitors.
White
Reveals dead pixels — pixels that stay black when the rest of the screen is white.
Red
Shows stuck green or blue subpixels that cannot display red.
Green
Shows stuck red or blue subpixels. Green is the most sensitive channel for the human eye.
Blue
Shows stuck red or green subpixels. Blue is the most common channel to develop stuck pixels.
Yellow
Reveals stuck blue subpixels — a pixel that cannot display yellow will appear blue.
Dead pixel vs stuck pixel vs hot pixel
- Dead pixel
- A pixel that receives no power and stays permanently black. Visible on white and colored backgrounds. Generally not fixable.
- Stuck pixel
- A pixel stuck in one color (red, green, or blue). Unlike dead pixels, stuck pixels sometimes respond to pixel-refreshing tools that rapidly cycle colors.
- Hot pixel
- A pixel that is always on — appears white or a bright color on a black background. More common on older screens and after heat damage.
Frequently asked questions
- How many dead pixels is acceptable?
- ISO 13406-2 classifies monitors by dead pixel tolerance. Most Class II monitors (the most common) allow up to 2 fully dead pixels. Check your monitor's warranty — many brands replace panels with even a single dead pixel.
- Can dead pixels be fixed?
- Truly dead pixels (no power) are permanent. Stuck pixels sometimes recover after running a pixel-cycling tool for several minutes, or by gently massaging the pixel with a soft cloth.
- How long should I look at each color?
- At least 5–10 seconds per color. Scan from corner to corner, then look at the center. Bright-room testing misses hot pixels — test in a dim environment for best results.
- Does this work on phones and tablets?
- Yes. Tap Start Test to open the fullscreen overlay. Tap the arrow buttons to cycle colors, or use the auto mode. OLED phone screens are particularly prone to stuck pixels.