Screen test
Open any pattern full screen. Use ← and → to step through them and Esc to exit.
Gradient
Ramps should run smoothly. Visible steps or color tints are banding, often from low bit depth or heavy picture processing.
Black level
In a dim room you should see squares from about 4 upward. If the low squares vanish, raise brightness; if the background looks gray, lower it.
White level
You should tell squares apart up to about 250. If the last few blend into white, lower contrast.
Dark gray 10%
In a dark room, look for brighter patches at the edges (backlight bleed) or blotches across the screen (clouding).
Gray 25%
Look for uneven patches, a brighter corner, or a ghost of a logo or taskbar (burn-in).
Gray 50%
Look for faint vertical or horizontal bands (dirty screen effect) and darker corners.
Gamma
Step back and squint. The patch that blends into the striped background is your gamma; 2.2 is the standard for computers and the web.
Sharpness
Fine lines and the checkerboard should look crisp or like an even gray texture. Halos around text mean sharpening is turned up; blur means the picture is being scaled.
Geometry
The circle should be round and the cells square. The thin red line should show on all four edges; if it doesn’t, the screen is cropping the picture (overscan).
Before you start
- Reset the display to its standard picture mode and turn off dynamic contrast and auto-brightness.
- Let it warm up for 10 minutes.
- Dim the room for the black level and dark gray patterns.
Every color
More screen tools
Dead pixel test
Five colors, one at a time, to find dead and stuck pixels.
Refresh rate test
See your screen’s real Hz and spot stutter.
Test pattern
Color bars and a test card at your native resolution.
Zoom light
A soft, warm light for video calls from a spare screen.
Background images
Plain color PNGs for desktops, phones and 4K.
Questions
What should I test on a new monitor?
Run the dead pixel test, then black level, the dark gray uniformity pattern in a dark room, and the gradient. Those catch most panel faults while you can still return it.
Why do the patterns look different on my phone?
Phones adjust brightness and color to the room. Turn off auto-brightness and night mode before testing.
Do I need to calibrate after this?
These patterns are for spotting faults and rough setup. For accurate color you need a hardware colorimeter.