Black Level Test
A row of patches climbing out of black, one 8-bit level at a time. Find the darkest one you can still tell apart from the background — that is where your display stops resolving shadow detail.
Jump to another test
Recommended · labels hidden for an unbiased result
Advanced display option
— click the darkest patch you can still distinguish from the background.
Turn the numbers off for an honest result, then back on to read which step you actually picked. Knowing a patch is there makes it much easier to convince yourself you can see it.
For a result worth trusting
- 1.Turn the room lights off. This test is meaningless in a lit room.
- 2.Let your eyes adjust for a minute before deciding.
- 3.Use your normal brightness — cranking it up will flatter the result and tell you nothing useful.
- 4.View straight on. Off-axis viewing lifts blacks on most LCD panels.
This finds a visual threshold, not a contrast ratio. Contrast is the ratio of two measured luminance values and needs a meter — why we do not print one.
What black crush actually is
Every display has a point below which it simply shows black. If your screen cannot separate level 8 from level 0, then every shade between them in a film, a game or a photograph arrives as the same flat black — the detail was sent, and the display threw it away. That is black crush, and it is the reason night scenes sometimes look like a black rectangle with a face in it.
Usually a setting, not a fault
Before blaming the panel, check three things. First, the RGB range: a source sending limited range (16–235) to a display expecting full range (0–255) crushes everything below 16, which is exactly what this wedge will show. Consoles, streaming boxes and GPUs connected over HDMI are the usual suspects. Second, the brightness control — on most TVs the setting labelled "Brightness" adjusts black level, not backlight, and turning it down crushes shadows. Third, any dynamic contrast or "black enhancer" mode, which crushes deliberately.
If the wedge looks correct on a different input or a different source device, the panel is fine and the signal chain is not.
What a good result looks like
On a decent display in a dark room, most people can separate level 1 or 2 from black. Losing everything below level 4 or 5 is unremarkable and you will rarely notice it in real content. Losing everything below level 10 is worth investigating — start with the RGB range.
OLED panels are a special case: they can switch a pixel fully off, so the step from level 0 to level 1 is the largest relative jump on the whole scale. Some OLED displays also handle near-black inconsistently across the panel, which is a uniformity problem rather than a black level one — the OLED gray test is the right tool for that. On LCD, if black looks lifted in the corners rather than uniformly, you are looking at backlight bleed instead.
What this test checks
- The darkest shade your display can still separate from black
- Whether shadow detail is being crushed by the panel or by the signal range
- How your black level changes with brightness and viewing angle
Related tests
Screen Uniformity Test
Gray levels that expose bands, clouding and dirty screen effect.
5% OLED Gray Test
5% grey banding check, near-black steps and a 3×3 uniformity map.
Backlight Bleed Test
Dark slides plus an angle check that separates glow from bleed.
IPS Glow Test
A guided angle check that separates panel glow from real bleed.
Not sure what you are seeing?
Run diagnosisSave your observations
Create a report