Monitor Test — Full Screen Display Test Patterns
Most monitor problems are invisible on a desktop and obvious on a test pattern. This page steps through the patterns that matter — flat colour fields, greyscale wedges, uniformity checks and sharpness grids — so you can judge a panel on something other than how a photo looks.
What people use the monitor test for
Evaluate a monitor before the return window closes
Uniformity, banding, tint shifts and dead pixels are all things you want to find in week one, not month six.
Set brightness and contrast properly
The greyscale wedge tells you whether your black level is crushing shadow detail and whether your white level is clipping highlights. Adjust until you can distinguish every adjacent step.
Compare two displays fairly
Same pattern, same room, side by side. Far more revealing than opening the same photo on both, because a photo hides where each panel is failing.
Check scaling and sharpness
A fine grid pattern immediately reveals whether a display is running at its native resolution or being scaled — scaled output turns crisp single-pixel lines into soft grey ones.
How to use the monitor test
- 1Set the display to its native resolution and the browser zoom to 100%.
- 2Press F for fullscreen — patterns are meaningless with a browser bar in the way.
- 3Step through the patterns with the arrow keys, or use the pattern list.
- 4On the greyscale wedge, adjust brightness and contrast until every step is distinct.
- 5View flat fields from about arm's length, and off-axis too, to check viewing-angle shifts.
Frequently asked questions
What is banding, and why do I see it?+
Banding is visible stepping in what should be a smooth gradient. Usually it means the signal chain is limited to 6- or 8-bit colour, or a cable or driver is running a reduced colour format like YCbCr 4:2:0. Check the display's OSD and your GPU settings before blaming the panel.
Is my panel faulty if the corners are darker?+
Some corner falloff is normal on nearly every LCD — perfectly uniform backlighting is expensive. It becomes a defect when it is severe, blotchy rather than gradual, or clearly visible in ordinary use rather than only on a flat grey field.
Do I need to install anything?+
No. Everything on whitescreen.studio runs inside the browser tab you already have open. There is nothing to download, no extension and no account.
Is it free?+
Yes, all of it, with no sign-up and no usage limit.