Screen Brightness & Calibration Test
Four quick visual checks to see how well your screen handles black, white, and the shades in between. These are visual sanity checks, not a substitute for a hardware calibrator — but they'll catch the obvious problems in under two minutes.
1. Black level
Go full screen on pure black in a dim room. It should look genuinely black, not a lifted, hazy grey. A grey-looking "black" usually means your brightness or backlight is set too high, or the panel has weak contrast.
2. White level
Go full screen on pure white. Look at the corners and edges against the centre — noticeable dimming toward the edges (vignetting) or a colour tint in one corner points to a backlight uniformity issue rather than anything you can fix in settings.
3. Greyscale gradient
A smooth black-to-white gradient should look continuous. Visible stripes or hard bands ("banding") instead of a smooth blend usually means the panel is running at reduced colour depth, or a colour profile is being applied too aggressively.
4. Checkerboard uniformity
A black-and-white checkerboard makes it easy to spot colour tint, glow, or backlight bleed around the edges of the screen — most noticeable on laptop and TN panels in a dark room.
Frequently asked
Why does my "black" look grey?
Most often the brightness or backlight setting is simply too high for the room you're in. LCD panels also have limited native contrast compared to OLED, so some grey lift on black is normal and expected — it's a question of degree.
Is this the same as proper colour calibration?
No. These are quick visual checks using your eyes. Proper calibration for colour-critical work (photo or video editing) needs a hardware colorimeter and calibration software, which measures actual light output rather than relying on how a pattern looks to you.
What causes banding in the gradient test?
Usually the screen or graphics output is running at a reduced bit depth (for example 6-bit instead of 8-bit per channel), or a colour profile or "smart" display mode is over-processing the image. Checking your display settings for the native colour depth is the first thing to try.
Looking for dead or stuck pixels instead? Try the dead pixel test.