Monitor Brightness Test
Set your monitor’s brightness by eye and check that dark detail survives without being crushed or washed out. The full-screen test cycles through a shadow-detail pattern, a grayscale ramp and solid fields — a visual aid, since a browser can’t read nits.
← → switch patterns
For accurate results keep browser zoom at 100% and test on the display you want to calibrate.
What each pattern checks
Set brightness so the darkest patch or two vanish into black while the next few near-black steps stay just visible.
A smooth black-to-white ramp with no sudden jumps, and dark detail near the left that is neither crushed nor raised to grey.
Even, distinct steps from black to white — each band should differ from its neighbours across the whole range.
A clean, uniform white field for perceived maximum brightness — check for dark corners, tint or uneven backlight.
A flat 50% gray field — look for blotches, banding or colour casts across the panel.
How do I set my brightness?
- Dim the room and turn off auto- or adaptive-brightness.
- Open the shadow-detail pattern and give your eyes a minute to adjust.
- Lower brightness until the 0 patch merges fully into black.
- Raise it just until the next near-black steps (1, 2, 4) become faintly visible.
- If every patch glows grey, brightness is too high — back it off until pure black looks black.
How do I use this brightness test?
Start the full-screen test and step through the patterns with the arrow keys or a click. Work in the shadow-detail pattern first — it’s the one the brightness control is meant to set. Dim the room, let your eyes adjust, then raise brightness until the lowest near-black patches are just barely distinct from the pure-black surround. If the 0 and 1 patches glow grey, brightness is too high and blacks are raised; if the first several vanish into black, it’s too low and shadow detail is crushed. Aim for the point where the darkest step or two disappear and the next few stay faintly visible.
Brightness vs contrast: what does each control do?
On almost every monitor the Brightness control sets the black level — how much light the panel emits for the darkest signal — while Contrast sets the white level. Set brightness with a dark pattern so black stays black without swallowing detail, and contrast with a bright pattern so white stays clean without clipping; the two interact, so expect a couple of passes. Use the sibling Black Level, Contrast, White Level and Gamma tests to fine-tune the rest of the tonal range.
How bright should your monitor be?
Screen luminance is measured in nits (cd/m²). A typical office or living room target is around 120 cd/m² — roughly 80–120 nits suits a dim room, while 150 nits or more helps in bright daylight. The goal is to match the screen to the light around it: much brighter than the room is a frequent cause of eye strain, and too dim makes you lean in and lose shadow detail. Lower it at night, raise it by day, and let your eyes settle before judging.
How do I adjust brightness?
| Where | How to adjust |
|---|---|
| Windows laptop | Settings › System › Display › Brightness, or the brightness keys on the top row. |
| Windows desktop | Laptop-style sliders often do nothing on an external monitor — use the monitor’s own buttons (OSD). |
| macOS | System Settings › Displays, or the brightness keys; external displays may need hardware buttons. |
| Monitor OSD | Press the physical menu button, find Brightness (separate from Contrast), and adjust on the shadow pattern. |
| Auto-brightness | Turn off any ambient-light or adaptive-brightness feature so the panel doesn’t change under you. |