What Is a Monitor Gamma Test?
A monitor gamma test measures the relationship between input signal value and displayed brightness. The sRGB standard targets gamma 2.2 — meaning a value of 50% in software should produce roughly 22% perceived brightness on screen. Wrong gamma washes out shadows or crushes highlights, throwing off color accuracy.
This tool uses the classic stripe-to-solid match pattern. The left side has alternating 1px black and white lines that average to 50% brightness when blurred. The right side is solid gray. You adjust the slider to change what gray value the solid side displays. When the two sides blend visually (squint or step back), the slider value equals your monitor's gamma.