White Screen

What a white screen is useful for

A blank white page turns any monitor, laptop, tablet or phone into a large, even light source. People use it as a soft fill light for video calls and selfies, as a makeshift light box for tracing drawings, to read a document held against the screen, or simply to find something under a desk at night. Because the whole display glows evenly, the light is softer than a single bulb or a phone flashlight. To see how it looks on camera before a call, open the webcam test on the device you will use.

Other solid colors have practical uses too. A black screen makes dust, fingerprints and smudges stand out when you clean your display. Red, green and blue screens help you spot pixels that are stuck on one color (the dead pixel test steps through all the test colors for you), and a custom color lets you create a gentle mood light or a colored background for product photos.

How the brightness slider works

Your screen’s real brightness is controlled by its backlight (or, on OLED panels, by how strongly each pixel is driven), and only your operating system can change that. A web page can only decide which color each pixel shows. The brightness slider therefore mixes the chosen color toward black: at 50% a white screen becomes medium gray, and a red screen becomes a darker red.

This is useful when full white is too harsh, for example in a dark room, but it can never make the display brighter than your current system brightness. If you need maximum light, set the slider to 100% and raise the brightness in your device settings.

Checking a display for backlight bleed and uneven brightness

LCD monitors and laptop screens are lit from the edges or from behind. When the panel is not perfectly sealed, light leaks around the edges, which is called backlight bleed. To check for it, choose black, open full screen, lower the room lights and look straight at the screen from your normal distance. Some glow at the corners is normal on IPS panels (often called IPS glow, which shifts as you move your head); bright, fixed patches are bleed.

A white or mid-gray screen at full size is good for spotting the opposite problem: uneven brightness, dark corners or a faint tint on one side of the panel, sometimes called uniformity problems. If you just bought a monitor, do this check within the return period.

Full screen on different devices

The “Full screen” button uses your browser’s full-screen mode, which hides the address bar, tabs and taskbar. While full screen is on, the mouse pointer disappears after two seconds without movement and the page asks the browser to keep the screen from going to sleep. Press Esc, or click or tap anywhere, to go back. Where a browser does not allow full screen, as on iPhone, the color covers the whole browser window instead and the same exit controls apply.