Red Out Screen

White Out Screen’s red display is a free online tool that fills your monitor with a pure red background. Used for preserving night vision during astronomy, dark room safe lighting, red subpixel testing and photography — no download or signup required.

White Black Red Green Blue Yellow Orange Pink Purple

F or Space — Fullscreen

ESC — Exit fullscreen

← → — Cycle colors

R — Reset color

What people use it for

🔭 Astronomy and Night Vision

Red light is the least disruptive colour to night-adapted eyes. Astronomers use red screens to read star charts and equipment settings without losing dark adaptation.

🌑 Dark Room Safe Light

Red is used in photography dark rooms as a safe light that doesn’t expose photographic paper — replicate this digitally with a red screen.

🖥️ Red Pixel Testing

Isolates red subpixel defects that are invisible on white or mixed colour displays.

💡 Mood Lighting

Creates warm dramatic ambient lighting for photography, video production or atmospheric room lighting.

😴 Sleep Friendly Light

Red light has the least impact on melatonin production, making it the most sleep-friendly screen colour for late night use.

Screensavers

📀

DVD Screensaver

Pro tips

Use Yellow screen for comfortable late-night reading — warmer and less disruptive than white.
Press F or click the screen to launch true fullscreen mode instantly.
Use Red screen to preserve night vision while stargazing — red light is least disruptive to dark adaptation.
Use Green screen as a chroma key background for webcam effects in video calls.
Adjust the Lightness slider to dial in the exact brightness you need without touching your system settings.
Download any color at up to 8K resolution as a PNG — great for design mockups or wallpapers.

Frequently asked questions

Why do astronomers use red light?

Human eyes take up to 30 minutes to fully adapt to darkness. Red light allows astronomers to read star charts, check equipment and take notes without destroying this dark adaptation, because the eye is least sensitive to red wavelengths at night.

Does a red screen help preserve night vision?

Yes. Red light has minimal impact on the eye’s rod cells which are responsible for night vision. Using a red screen instead of white or blue significantly reduces the time needed to re-adapt to darkness after checking a screen.

How do I test red subpixels on my monitor?

Display a fullscreen red background and look for any dark or discoloured spots. Dead red subpixels appear as black patches against the red background — defects that are completely invisible on white screens.

Is red light better for sleep than white light?

Yes. Red light has the least impact on melatonin production compared to white or blue light. Using a red screen at low brightness is the most sleep-friendly way to use a monitor late at night.

Is the red screen tool free?

Completely free. No signup, no ads, no tracking. Open it in your browser and it works instantly.