Gradient Test

A good display renders a gradient as a smooth change with no visible steps. Banding shows up as distinct stripes where the transition should be continuous.

The ramp should look smooth from black to white; stripes or blocky steps are banding, and the dark end is the usual trouble spot.

Runs entirely in your browser. Nothing is uploaded or stored.

How to use

  1. Press Start test to show the gradient fullscreen.
  2. Move through the gradients. Look for stripes, blocks, or sudden jumps in tone.
  3. Check the dark end of the grayscale gradient carefully. That is where banding is most common.
  4. Compare the horizontal and vertical versions. Banding in only one direction can point to a scaling or signal issue.

What this test can detect

  • Banding: visible stripes in what should be a smooth ramp.
  • Posterization: blocky steps in color gradients.
  • A dark region that jumps from black to gray instead of easing in.
  • Color tint in the neutral gray gradient.

Important

  • Browsers draw gradients with 8 bits per channel, so a faint amount of stepping is inherent and does not mean your display is faulty.
  • Dithering by the graphics driver or display can hide or reveal banding. Results can differ between devices showing the same image.
  • Very wide screens spread each of the 256 steps over more pixels, which makes them easier to see.