Dead Pixel Check

Gradient / Banding Test

A perfect screen renders these ramps as seamless transitions. Visible stripes — banding — reveal bit-depth limits, aggressive processing or a cable/driver issue.

7 full-screen colors · click, tap, swipe or press Space to advance · Esc to exit

Free · No download · No sign-up · Runs locally in your browser

smooth banding

Judging what you see

  • Faint, evenly spaced stripes on the smooth ramps = banding.
  • The 16-step slide should show sixteen clearly distinct bars.
  • If the darkest steps merge into one, the display is crushing blacks.
  • Disable night mode and dynamic contrast before judging.

Where banding comes from

An 8-bit panel has 256 levels per channel; stretched across a full screen, the steps between neighboring levels can become visible as stripes, especially in dark grays. But the panel is only one suspect: banding is just as often introduced by the signal path — a 6-bit+FRC laptop panel, "limited range" RGB over HDMI, aggressive TV picture processing, or a graphics driver set to a lower output depth. If banding appears here but not on another device showing the same page, check your display settings before blaming the panel.

Note that this is a visual aid test: a browser cannot measure your panel's true bit depth. What it can do is show you whether the end-to-end result — panel, cable, GPU and settings together — renders gradients cleanly.

Seeing stripes on flat gray rather than on ramps? That's a uniformity problem instead — run the screen uniformity test.