Red Screen
A pure red screen that drives every red subpixel at full strength. It's the quickest way to check red color purity, hunt for stuck or dead subpixels, and look for tint or brightness that drifts across the panel. Switch to any other color from the controls whenever you need it.
What you can use it for
- Push every red subpixel to check it lights evenly
- Find pixels that stay dark or won't show red
- Spot tint shifts and uneven brightness on a single color
- Cast a red glow for ambient lighting or photography
How it works
- 1. Customize. Open the Customize panel to set text, colors, theme, and animation speed to your liking.
- 2. Go fullscreen. Click Fullscreen for an immersive, distraction-free display on any screen.
- 3. Done. No login, no install, nothing to download — it runs instantly in your browser and your settings are remembered.
Frequently asked questions
What does a red screen test?+
It sets the whole panel to full red, so every red subpixel is pushed to maximum. Dead subpixels and uneven patches stand out right away.
Can I switch colors?+
Yes. The color picker jumps to any solid color, so you can run a full red, green, and blue check in seconds.
More display & light tools
White Screen
Fill your whole display with pure white in one click.
Black Screen
Turn your whole display solid black in one click.
Green Screen
Fill the display with solid green for color and pixel checks.
Blue Screen
Fill the display with solid blue for color and pixel checks.
Gradient Background
A still, fullscreen color gradient from curated palettes.
Zoom Light
Use your screen as an adjustable key light for video calls.
Selfie Light
A bright, adjustable fullscreen light for selfies and makeup.
Warm Light
A soft, warm fullscreen light that's easy on the eyes.
Cool Light
A crisp, cool daylight fullscreen light for focus and photos.