Black Level Test
Check how deep your display’s black really is and whether it holds on to shadow detail. Run the full-screen pure-black field to judge true black and spot raised, grey blacks, then use the near-black step patches to see whether the darkest shades are crushed away. Works best in a dark room on the display you want to check.
← → switch patterns
Test in a dark room at 100% browser zoom, on the display you want to check. Black level is set by the monitor’s Brightness control.
What each pattern checks
A deep, even, inky field with no grey wash. In a dark room, note any raised grey cast or corner glow — true black should look close to the screen being off.
Near-black patches on pure black. All but the lowest (0) should be faintly distinguishable; if the first several vanish, blacks are crushed. If even 0 glows grey, blacks are raised.
A smooth ramp from black into dark grey with no hard steps or banding. Watch the far-left end for where shadow detail first separates from pure black.
How to set your black level
- Dim the room and turn off adaptive or ambient-light brightness.
- Open the shadow-steps pattern and let your eyes adjust for a minute.
- Lower the monitor’s Brightness (OSD, not the OS slider) until the 0 patch merges fully into black.
- Raise it just until the next near-black steps (1, 2, 3) become faintly visible.
- If every patch still glows grey at minimum, the panel simply has a high native black level.
What the three patterns show
- Pure black: a full #000 field to judge how dark true black looks and to spot raised (grey) blacks and any glow in a dark room.
- Shadow-detail steps: patches at code values 0, 1, 2, 3, 4, 6, 8, 10, 12 and 16 on pure black. Every patch except the lowest should be faintly distinguishable; if the first several vanish, your blacks are crushed.
- Black-to-dark-grey gradient: a smooth ramp from #000 into dark grey that shows where shadow detail begins to separate from black.
Black level, raised blacks and crushed blacks
Black level (or black point) is how much light the screen still emits when it is asked to show pure black. A low black level looks deep and inky; a high one looks washed-out grey, which is called raised black. On most LCDs the black level is set mainly by the monitor’s Brightness control, which shifts the whole low end up or down. Set Brightness too high and near-black tones glow grey (raised blacks); set it too low and the darkest shades merge together and disappear (crushed blacks), taking real detail in shadows with them. The near-black step pattern is the quickest way to see which way your panel is leaning.
IPS glow, backlight bleed and true black depth
A raised or uneven black on an LCD is not always a Brightness problem. IPS panels show IPS glow — a warm haze in the corners that shifts and fades as you move your head. Backlight bleed is brighter light leaking in from the panel edges and stays fixed regardless of viewing angle; our Screen Bleeding Test is built specifically for that. True black depth is different again: it is how little light the panel emits at all, set by the display technology. OLED pixels switch off completely for near-perfect black, while an LCD’s always-on backlight leaves a faint floor even at its best. This test helps you tell an evenly raised black (a Brightness setting) from localised glow or bleed (a panel trait).
How to set your black level
Black level is adjusted with the monitor’s Brightness control in the on-screen display (OSD), not the graphics-card brightness slider, and it is separate from Contrast, which sets the bright end. Work in a dim room with adaptive or ambient-light features turned off, and give your eyes a minute to adjust before judging near-black tones. For the whole-picture luminance and grayscale ramp, use the Brightness Test alongside this one; for fixed edge and corner light leak, use the Screen Bleeding Test.