Gamma Test

How the comparison works

Each column has two halves. The top half is a pattern of black and white lines, one device pixel thick, which averages to exactly half the light of white. The bottom half is a solid gray. Gamma describes how a display turns a number into light: with a gamma of 2.2, half the light comes from level 186, not from level 128. Each column's gray is the level that should match the lines at that gamma: 174, 180, 186, 191, and 195.

1. 1

   Open it full screen and set browser zoom to 100%, so the lines stay one pixel thick.

2. 2

   Step back or squint until the lines blur together into a flat tone.

3. 3

   Find the column whose two halves look most alike. Its label is your display's approximate gamma.

4. 4

   Look straight on. Gamma changes with viewing angle, especially on VA and TN panels.

What the result means

Most content for computers and the web is made for a gamma of about 2.2, so a match near 2.2 means images and photos should look as intended. A lower value makes dark areas look washed out; a higher value makes them look heavier and can hide shadow detail. Many displays have a gamma setting in their menu, and operating systems can adjust it as well.

For shadow and highlight steps, use the Screen Contrast Test; for smooth ramps, the Color Banding / Gradient Test.

If no column matches

If every column looks wrong, the lines are probably not landing on single pixels: check that browser zoom is 100%, that the display runs at its native resolution, and that you are not viewing this through screen sharing or a recording. Very low brightness and strong viewing angles also shift the match. Try again straight on, at a normal brightness.