Full Red Screen
Fill your whole screen with pure red to test the red sub-pixel channel and reveal dead pixels on a colored field. Free and runs in your browser.
Pick a color
Press Esc to exit, or use the ← → arrow keys to switch colors while in full screen.
What is it for?
About Full Red Screen
The Full Red Screen tool floods your display with pure red (#FF0000), driving the red sub-pixel of every pixel to maximum while the green and blue stay off. That isolation is exactly what a proper pixel test needs: a sub-pixel that fails only in the red channel is invisible on plain white or black.
On a solid red field, defects jump out — a dead red sub-pixel reads as a dark dot, while a stuck green or blue sub-pixel shows as an off-color speck. A red screen also exposes tint problems: color banding, patchy uniformity or a panel edge rendering red noticeably differently from the center.
The page is free and entirely browser-based. Run it as one step of a full check — white, black, then each primary — using the arrow keys to switch colors without leaving full screen, and the custom picker if you want to test any other hue. A deep red screen also doubles as low-key ambient mood lighting.
How to use Full Red Screen
- Click the monitor preview or "Go full screen" to fill the display with pure red.
- Inspect the panel for dark dots or off-color specks against the red field.
- Check the corners and edges for uneven tint or brightness.
- Press → to advance to the green and blue tests, or Esc to exit.