DeviTestBlack level and white saturation test
Twenty gray squares, each a little lighter (or darker) than the background. The more you can see, the better your screen handles shadows and highlights.
How to run the test
- Turn off auto-brightness and set brightness to the level you normally use.
- Open the test in full screen. Tap the squares to switch between the black and white tests.
- Count the squares you can clearly tell apart from the background. Square 1 is the closest to the background color.
How to read the result
- Black test — squares 1 to 3 invisible: normal on most screens.
- Black test — many squares invisible: shadow detail is "crushed" (lost in the dark). Dark movies and games will lose detail. Try raising brightness or lowering contrast or gamma settings.
- Black test — the background looks gray: the screen can't show deep black. Normal for many LCDs. On OLED, pure digital black should look very deep because the pixels switch off — allowing for room reflections and picture settings.
- White test — many squares invisible: highlights are "clipped" (bright detail turns flat white). Try lowering contrast or brightness on a monitor.
Results also depend on your room lighting and viewing angle, so compare screens in the same conditions. Night mode, blue-light filters and "vivid" color modes all change the result.