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Panel & Backlight

Black Level Test

Near-black steps to see how dark your panel really goes.

▶ Start full-screen testTap for controls · Esc to exit

How to use

  1. 1Dim the room and set brightness to your normal level, then click Start.
  2. 2Each vertical band is slightly brighter than pure black (the number is its value).
  3. 3Note the lowest band you can still tell apart from pure black — that's your shadow floor.
  4. 4Press Esc to exit.

FAQ

How many steps should I see?

On a good display in a dark room you can usually distinguish the steps from value 2–4 upward. If low steps all look identical to black, shadow detail is being crushed (often a brightness/black-level or 'Limited' RGB range setting).

Should I turn brightness up until I see every step?

Not on a monitor: its brightness control mostly drives the backlight, which makes every step easier to see but also lifts black. Test at the brightness you actually use. On TVs, the setting called Brightness often controls black level itself, and that is the one to adjust.

Why do the dark bands glow toward the corners?

That's IPS glow or backlight bleed, not a shadow-detail problem: backlight showing through at an angle or leaking at the edges. Judge the steps from the center of the screen, and use the Backlight Bleed Test to look at the corners.

Tips

  • Dim the room and use your normal brightness — not maximum — to judge real shadow detail.
  • If the lowest steps all merge into black, check for a 'Limited' RGB range or a crushed black-level setting.

Related tests

Dead Pixel TestFull-screen solid colors to find dead, stuck, and bright pixels.Open test→Backlight BleedReveal LCD backlight leakage and IPS glow in a dark room.Open test→Brightness UniformityA 50% gray field, a 9-zone grid and a panning gray to spot uneven backlighting.Open test→Blooming TestA bright object on black to judge local-dimming halos.Open test→

Related guides

Learn more about what this test reveals and how to act on the results.

Backlight Bleed vs IPS Glow: What's the Difference?Both show up as light on a black screen, but they're different problems. Learn how to tell them apart and what's normal.Gamma Explained: Why Your Shadows Look WrongGamma controls how brightness is distributed between black and white. Here's how to check yours, why 2.2 is the standard, and how to set it.Why Do Blacks Look Grey? Full vs Limited RGB RangeWashed-out blacks or crushed shadows over HDMI are often an RGB range mismatch, not a bad panel. Here's how to spot it and how to set it right.How to Calibrate Your Monitor Without a ColorimeterGet noticeably better color and contrast by eye using built-in OS tools and test patterns — no hardware required, and no guesswork either.