What a white screen is used for
- Lighting your face on a video call when the room is dark
- A light box for tracing paper, checking negatives or reading a slide
- Spotting dead, stuck or dust-obscured pixels, which show as dark specks against white
- Checking a laptop screen for scratches, smudges and pressure marks
- A blank background for photographing small objects
White screen online: #FFFFFF at full screen
White is the screen every other test starts from. Because all three subpixels are driven at full output, a white field exposes anything that is not working: a dead pixel reads as a black dot, a stuck subpixel as a coloured one, and dust under the glass as a grey smudge that does not move when you wipe the surface.
It is also the brightest thing a display can show, which is why it doubles as a light source. Turn the brightness up, angle the screen towards your face, and a laptop becomes a usable fill light for a call — softer and far less harsh than a phone torch.
On an OLED or AMOLED panel, a full white field is the worst case for power draw, because every subpixel is lit. If you are checking battery behaviour or panel heat, this is the page that will show it fastest.
How to get a full screen white background
Press the fullscreen button on the player above, or the F key. Escape returns you to the page. On a desktop browser F11 does the same job and hides the browser's own toolbars as well.
The colour box is a control, not a picture: use the hex field to enter any value, pick another shade from the palette, or download the current colour as a PNG at your screen's resolution. Whatever you set is written into the address bar, so the link you copy reproduces exactly what you are looking at.