RGB Cycle Test
Automatically cycles through Red, Green, and Blue fullscreen. Finds stuck subpixels in seconds.
Space pause/resume · Esc exit
How RGB cycling finds stuck pixels
Each pixel on your monitor is made of three subpixels: red, green, and blue. A stuck subpixel gets locked in one state — always on or always off — while the rest of the display responds normally.
By displaying a pure red screen, any pixel that cannot show red will appear dark. Switch to green and stuck green subpixels become visible. The same logic applies to blue. Three passes, complete coverage.
Choosing the right speed
0.5–1s
Fast scan — good for finding obvious stuck pixels quickly.
2–3s
Balanced — enough time to examine each color carefully.
5–8s
Slow — best when you want to look closely at specific areas.