What this test can tell you
The page draws a solid color for you to inspect visually. Compare more than one background and distinguish a mark fixed to the display from something that moves with page content.
It does not automatically detect defects, measure color accuracy or repair a panel. Browser fullscreen, color settings, brightness and room reflections affect what you see.
How to use it
- Press “Open fullscreen” (or the F key) to fill the entire screen with white.
- Turn up your display brightness for a stronger light.
- Set the timer if you want the screen to close automatically.
- Press Esc, tap or click to leave fullscreen.
What a white screen is good for
Use white as a fill light for a call, a tracing background or a way to compare dark dots and uneven areas. A mark on one background is a reason to compare other colors, not a diagnosis of its cause.
Checking your display
Inspect from a consistent angle at a comfortable brightness. Reflections, display settings, night-light filters and the panel can all affect the appearance. For physical cleaning, turn off the display and follow the manufacturer’s instructions; inspect again afterwards.
Not working? Try these fixes
Fullscreen does not open on iPhone
Safari on iPhone limits fullscreen for web pages. The page still fills the browser window; rotate to landscape and hide the toolbar by scrolling, or add the page to your Home Screen for a borderless view.
The screen dims or turns off
This page asks your browser to keep the screen awake. If it still dims, disable battery saver and check the auto-lock setting of your device.
The white looks yellow
Night Light (Windows), Night Shift (Mac, iPhone) or an eye-comfort mode is active. Turn it off for true white.
Frequently asked questions
How bright should I set the white screen?
Use a comfortable brightness for the room and task. Avoid staring at an unnecessarily bright display and stop if it is uncomfortable.
Can I use it as a ring light?
Yes. Put the white screen on a second device or monitor next to your camera for soft, even light on your face.
What color code is the white screen?
It is pure white: #FFFFFF or RGB(255, 255, 255).