Black level test
Twenty steps just above black and twenty just below white. On a well set-up display you can make out almost all of them. Missing steps mean shadows or highlights are being thrown away.
Near-black: values 1–20 on 0
Near-white: values 235–254 on 255
A dim room helps with the black steps. OLED and good VA panels usually show from step 1–3; IPS may show slightly raised black but all steps.
What your result means
| Result | Likely cause | Fix |
|---|---|---|
| Black steps below ~16 all look the same | Display in limited range, PC sending full | Set monitor "HDMI black level" / "RGB range" to full, or match the GPU setting |
| Black looks grey, all steps visible but washed out | PC sending limited range to a full-range display | NVIDIA: Output dynamic range = Full. AMD: Pixel format RGB 4:4:4 Full. Intel: Quantization range = Full |
| Only the first 5–8 steps are lost | Brightness/black level set low, or gamma too high | Raise black level one notch; check the gamma test |
| Top white steps merge | Contrast set too high, highlights clipped | Lower contrast until 250–254 separate |
Questions people ask
Why can't I see the first few black squares?
Either brightness is set too low, the display crushes shadows (a gamma or picture-mode issue), or there is an RGB range mismatch: the PC sends limited range (16–235) while the monitor expects full (0–255), or the other way round.
What is limited vs full RGB range?
PCs normally use full range, where black is 0 and white is 255. Video and TVs traditionally use limited range, where black is 16 and white is 235. If the two ends disagree, blacks look grey and washed out, or shadows and highlights are clipped. Set both the GPU output and the display to the same range, usually full for a PC monitor.
What does the brightness control actually change?
On many monitors it changes backlight strength. On TVs and some monitors, "Brightness" shifts the black level instead, and "Contrast" sets the white level. Use this page's steps to set those so the first visible step sits just above black and the brightest steps don't merge.