Five pixel-exact patterns check your monitor contrast: 32-step RGB bands, an ANSI 4x4 checkerboard, white-clip patches, black-crush squares and a gamma fusion check. Run the guided test to set the Brightness and Contrast knobs correctly and get a verdict for each step.
Before you test
Set browser zoom to 100%.
Disable Dynamic Contrast, Eco mode, Night Light and Windows HDR.
Set GPU output to RGB Full (0-255) with a matching monitor Black Level setting.
Sit centred and view straight-on - VA and TN panels shift near black off-axis.
Let the display warm up for 15-30 minutes.
Looking for text or accessibility contrast checking? That is a different test - this page tests your display hardware.
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Patch value186
Target: RGB 186 = gamma 2.2 (sRGB)Set browser zoom to 100% (or display scaling to 100% / 200%) for an accurate gamma reading.
Your result
Your result
Calibration summary
White-clip tip: if the brightest patches look tinted instead of grey, one RGB channel is clipping first - lower Contrast or reset the monitor RGB gain controls.
Knob naming: on desktop monitors, Brightness drives the backlight. On TVs, Brightness sets the black level (use the black-crush squares) and Contrast sets the white level (use the white-clip patches).
Typical native contrast by panel type
Panel
Native contrast
TN
600–1200:1
IPS
700–1500:1
VA
2500–5000:1
OLED
Effectively infinite
If an IPS monitor shows slightly grey blacks beside white, that is panel physics - no setting fixes it. Ignore "dynamic contrast" spec numbers; only native contrast matters.
A browser cannot measure your contrast ratio in nits - these patterns reveal calibration and panel-class problems by eye. Spec-sheet "dynamic contrast" numbers are marketing; only native contrast matters.