For a night light, turn your screen brightness down in your device settings and use the slider here to make the red darker still.
About the Red Screen
This page is a plain red screen. Press Full screen and your whole display turns red — no buttons, no text, nothing else.
A dim red light is gentle on eyes that are used to the dark. Stargazers and campers use red light to read a map or find things at night without losing their night vision. A red screen is also a simple mood or party light, and a test that shows faults in the red sub-pixels of a screen.
It runs in your browser. Nothing is installed and nothing is sent anywhere.
Features
- Opens red — the page is already red, one click for full screen
- True full screen — no menus or text on top of the light
- Brightness slider — make the red darker, down to 10 %, for a night light
- Keep the screen on — the screen does not go dark while the light is on
- Other colours — white, black, green, blue, yellow, pink or any colour you pick
- Hides the pointer — the mouse pointer and the hint fade away after 2 seconds
What people use a red screen for
- Stargazing and camping. After about 20 minutes in the dark your eyes see much more. Bright white light ruins that in a second. A dim red light lets you read a star map or find your things and keep most of your night vision.
- Night light. A dim red light in a bedroom or a baby's room gives just enough light to move around.
- Party and mood light. Fill a room with red for a party, a photo or a film night.
- Red pixel test. On a full red screen, a pixel whose red sub-pixel has failed shows as a dark dot.
- Photo and video effects. Hold a phone with a red screen near a face or an object for a red glow in a photo.
Red light and night vision: good to know
- Keep it dim. Any bright light, red too, makes your eyes adjust back to the light. Turn the screen brightness down and use the slider.
- Red light is not completely safe for night vision — it is just the gentlest colour. Use as little light as you need.
- Turn night mode off if the red looks orange.
- A phone screen is still bright at the lowest setting in a very dark place. Some people put red tape or red film over the screen as well.
How to use it
- Press Full screen — the whole display turns red
- Move the Brightness slider down for a softer night light
- Move the mouse or tap to see the Exit button again
- Tap a colour below the screen to change the colour, or press ← → in full screen
- Press Esc or double-click to leave full screen
Frequently asked questions
Why do astronomers use red light?
Our eyes need about 20–30 minutes to get used to the dark. Dim red light disturbs that much less than white light, so you can read a map or adjust a telescope and still see faint stars.
Is a red screen good before sleep?
Many people find a dim red light calmer than a bright white one in the evening. Keep it dim. This page is a light, not a sleep treatment.
Can a red screen find dead pixels?
A red screen shows a failed red sub-pixel as a dark dot. To check every kind of fault, also look at white, black, green and blue. The Screen Test steps through them all.
Why does the red look orange?
Night mode or a blue-light filter is on, or the screen brightness is very low. Turn off Night Light, Night Shift or Eye Comfort while you use it.
Is it free?
Yes. It is free, with no sign-up and no download.
Related tools
- Black Screen — a plain black screen, to keep a screen dark
- White Screen — a plain white light for calls, tracing and reading
- Moon Phase Calculator — tonight's moon, for planning a night under the stars
- Online Compass — find north with your phone
- Screen Test — every test colour in a row, to find dead and stuck pixels
