Monitor gradient test

How to run the gradient test

1. Press Full screen. Use your normal brightness in a dim room.
2. With Steps: 256 (smooth), look along each ramp from left to right from your usual viewing distance.
3. Switch to 64, 32 and 16 steps to see what deliberate banding looks like, then return to 256 and compare.

Reading the ramps

• Smooth ramps at 256 steps: the signal and the panel show the full 8-bit range in this test. On a large screen viewed up close, very fine steps can still be visible; that is normal for 256 levels.
• Clear bands at 256 steps, especially if they look like the 64 or 32 step setting: gradation is being reduced. Common causes are colour profiles or calibration curves, night-light or blue-light filters, brightness or contrast changes in the graphics driver, a reduced colour format or bit depth on the connection, and picture modes on the screen.
• Coloured stripes in the grey ramp (pink or green bands): the colour channels are not balanced across the range, often from a colour profile, white balance setting or picture mode.
• The dark end merges into one black: shadow levels are crushed. Check with the black and white level test.

What this test cannot tell you

The browser draws this pattern with 8 bits per channel, so it cannot show 10-bit gradation or prove a panel's native bit depth. Graphics drivers and panels may also use dithering (FRC), which can hide banding in this test while it remains visible elsewhere, or the other way round. Use the result to compare settings on your own screen, not as a specification check.

For uneven brightness on flat greys, use the monitor uniformity test; to inspect single colours full screen, use the screen colour test.