Monitor Brightness Test – Gamma, Black and White Levels
Check that your monitor shows every step from black to white, whether its gamma looks right and whether brightness is even across the panel. Adjust the monitor's brightness and contrast while you watch the patterns.
0% (Black)
#000000
10%
#1A1A1A
20%
#333333
30%
#4D4D4D
40%
#666666
50%
#808080
60%
#999999
70%
#B3B3B3
80%
#CCCCCC
90%
#E6E6E6
100% (White)
#FFFFFF
Adjust to test monitor brightness response
Keyboard Shortcuts
Found a stuck pixel? Try to revive it with the Dead Pixel Fixer
How to Use This Tool
What is this Test?
A brightness test shows whether your monitor can display every shade between black and white. The gray ladder steps from 0 to 100 percent: if the darkest steps merge into black, shadow detail is lost; if the brightest merge into white, highlights are clipped. The gradient reveals banding, the bars put all shades side by side, and the flicker mode alternates black and white at a speed you choose. It is a visual check: measuring brightness in nits or an exact gamma value needs a colorimeter. For uneven brightness across the panel, a full white screen is easier to judge.
Test Modes Explained
- Gray Ladder: Shows 11 gray levels (0-100%) to test brightness uniformity
- Gradient: Smooth transition from black to white to detect banding
- Bars: Separate bars of each brightness level for detailed comparison
- Flicker: Black/white flicker pattern to detect monitor flicker issues
What to Look For
- Banding: Visible bands or stripes in gradients indicate poor color depth
- Brightness Shifts: Uneven brightness across the display suggests backlight issues
- Color Casts: Tints in gray levels may indicate color balance problems
- Dead/Stuck Pixels: Colored spots or dark areas in uniform displays
Testing Tips
- •Ensure your monitor is fully warmed up (30+ minutes)
- •Test in a darkened room to better see brightness differences
- •View the screen at arm's length for optimal perception
- •Use fullscreen mode (press F) for immersive testing
- •View each gray level carefully and note any anomalies
Keyboard Shortcuts
How this test works
The ladder and bars use exact gray values from 0 to 100 percent in 10 percent steps, and the gradient runs smoothly from black to white, so any steps you cannot tell apart are lost by your monitor or its settings, not by the page. The flicker mode alternates black and white at the speed you choose, after a warning for people sensitive to flashing light.
Pro Tip: Set your monitor's own brightness to a comfortable level for your room first, then adjust contrast until the top steps stay distinct and the black level until the first steps above black are just visible. The Display Opacity slider dims the test pattern without changing any monitor setting. When text still looks hard to read afterwards, check it with the contrast test.
What is a Brightness Test?
Brightness Uniformity
Measures how evenly your display maintains brightness across the entire screen. Uneven brightness creates dark corners or bright spots.
- ✓ Detect backlight bleeding
- ✓ Identify dark corners
- ✓ Check edge brightness
Gamma Response
Tests the display's tone curve and how it renders midtones. Proper gamma (2.2) ensures accurate color representation and smooth gradations.
- ✓ Verify tone gradation
- ✓ Test gamma curve accuracy
- ✓ Check midtone rendering
How to Use This Brightness Test
Adjust Monitor Settings
Set your monitor to standard settings or factory defaults for consistent results.
Run the Brightness Ladder Test
Look at the 11-step brightness ladder. Each step should be distinguishable without banding.
Check for Gradient Banding
If you see distinct bands instead of smooth gradations, your display has limited bit depth or dithering issues.
Verify Uniformity
Check that brightness remains consistent across all areas of the screen, especially corners.
💡 Professional Tip
If your monitor shows significant brightness inconsistencies, backlight bleeding, or fails uniformity tests within warranty, contact the manufacturer. Most premium monitors have strict brightness uniformity standards (typically ≤20% variation).
Common manufacturers: Dell, LG, ASUS, BenQ, Samsung, HP, AOC, MSI
Frequently Asked Questions
What gamma should my monitor use?
Gamma 2.2 is the standard for Windows, macOS and the web, and it is the right choice for almost everyone. Gamma 2.4 is meant for watching or grading video in a dark room. If your monitor has a gamma setting, start at 2.2.
Why can't I see the darkest steps?
Your black level is too low: brightness or black level is turned down too far, the gamma is set too high, or light in the room washes out the shadows. Raise the monitor brightness or black level setting until the first steps above black just become visible.
Why do the brightest steps all look the same?
The contrast setting is too high, so near-white shades are clipped to pure white. Lower the contrast until you can tell the top steps apart again.
What causes banding in a gradient?
Visible steps in a smooth gradient usually come from a 6-bit panel that fakes extra shades with dithering, from color profile or graphics driver adjustments that reduce the number of shades, or from compressed video. A little banding in very slow, dark gradients is normal even on good monitors.
How bright should my monitor be?
Match the room. A common target is around 100 to 150 nits for office work in a normally lit room, and about 120 nits for photo editing. A quick check: a white page on screen should look about as bright as a sheet of paper next to it.
Can this test calibrate my monitor?
It helps you set brightness, contrast and gamma by eye, which fixes the most common problems. Accurate calibration of color and white point needs a hardware colorimeter.
Written by R. Ottens, front-end developer & image editing specialist.