Gray Screen
This is 50% gray — RGB 128, 128, 128 — the neutral reference that photography and video have used as a metering target for decades. All three sub-pixels run at equal, half output, which makes any colour cast in your panel immediately visible.
What people use the gray screen for
Set a custom white balance
Photograph a screen showing neutral gray under your actual shooting light and use it as the white balance reference. Not as accurate as a proper grey card, since the screen emits rather than reflects light — but far better than guessing.
Expose to a known midpoint
Reflective meters are calibrated around middle gray. A flat neutral field gives you something predictable to meter against when you are setting a baseline exposure.
Reveal panel colour casts
Colour casts hide in white and disappear in black. On 50% gray a warm or cool bias in the panel is unmistakable, which is why calibration software leans on grey fields.
Neutral editing surround
Colour graders work against neutral grey walls because a coloured surround shifts your perception of what you are grading. Fill a second display with grey to get some of the same benefit.
How to use the gray screen
- 1Open the gray screen — it fills the page immediately, no button needed.
- 2Press F or use the fullscreen button to go edge to edge with no browser chrome.
- 3Use the brightness slider to dial the output up as a light source or down for a dark room.
- 4Move the mouse or tap once to bring the controls back; they fade out on their own after a few seconds.
- 5Press a number key or use the colour strip to jump straight to another colour.
Frequently asked questions
Is 50% gray the same as an 18% grey card?+
Not quite. An 18% grey card reflects 18% of the light hitting it — that is a reflectance value. RGB 128 is a digital code value which, after standard sRGB gamma, lands near 21–22% relative luminance. They are close enough for practical metering and often used interchangeably, but they are not defined the same way.
How do I make the gray screen fill my whole display?+
Press F (or click the fullscreen button) to enter true browser fullscreen, which hides the tab bar, address bar and taskbar. Press Escape to leave. On mobile, tapping the screen hides the controls; add the page to your home screen for a fullscreen launch every time.
What is the exact gray colour used here?+
#808080. You can copy it from the control bar, or open the colour picker to dial in any other value and keep it in the URL so the exact shade is bookmarkable.
Does this work on phones and tablets?+
Yes. It works in any modern browser on iOS, Android, Windows, macOS, Linux and ChromeOS. Nothing is installed and nothing needs an account.
Is it free, and are you tracking me?+
Free, with no sign-up. Every tool here runs entirely in your browser — no colour choices, screenshots or usage details are sent anywhere.