Gamma test
Four full-screen comparisons — gamma 1.8, 2.0, 2.2, and 2.4. Each shows fine stripes beside a solid gray patch; from a distance, the pair that merges into a single tone is your display's approximate gamma. Most screens should match near 2.2. Click or press → to change screens, Esc to exit.
Gamma FAQ
- What is display gamma?
- The curve that maps signal values to light output. Displays don't brighten linearly: a pixel value of 50% produces far less than 50% of maximum light. How much less is set by gamma — the sRGB standard targets roughly 2.2. Lower gamma washes out midtones; higher gamma darkens them and swallows shadow detail.
- How does this test work?
- Each screen splits in half. One side is single-pixel black and white stripes, which physically emit 50% of maximum light no matter what the display does. The other side is the solid gray that *should* look like 50% under one candidate gamma. Step through 1.8, 2.0, 2.2, and 2.4 from a normal viewing distance, squinting or stepping back — the screen where both halves blend into one tone is approximately your display's gamma.
- Why must the browser be at 100% zoom?
- The striped half only averages to exactly 50% light if each stripe stays one clean pixel. Browser zoom or fractional OS display scaling (125%, 150%) resamples the stripes into blended grays, which shifts the comparison and skews the reading. Use 100% zoom, and on Windows prefer testing on a display running an integer scale factor.