Six solid fields in one pass: pixels, backlight bleed, uniformity, and colour channels. This is the test to run on a monitor that just arrived, before the return window starts closing.
F to start, Space to advance, Esc to exit
Fields: white, black, grey, red, green, blue
How to run it
1
Dim room, adaptive settings off, real brightness
All three change what you see. Set them once, then do not touch anything during the pass.
2
Take the fields in order
Do not skip ahead. The order is doing work, which the first note explains.
3
Judge from your seat
Normal distance, normal angle. A fault you can only find with your nose on the panel is not a fault you will ever see.
Field notes
The field order is doing work.
White comes first while your eyes are still light-adapted, which is when smudges and dark pixels are easiest to catch. Black comes second because it gives your eyes the minute of dark adaptation they need before bleed is readable at all. Grey follows because by then you are adapted and grey sits in the middle of the panel’s range, where uniformity problems show best.
Jumping from a bright desktop straight to black and judging immediately is exactly how people talk themselves into returning a working monitor.
Last checked 2026-08-04
Grey is the most useful field and the one everyone skips.
Mid-grey puts every pixel in the middle of its range, so small luminance differences across the panel are at their most visible. Uniformity dips, dirty-screen effect, and retained images all show against grey when white clips them away and black buries them.
If you only have time for two fields, use grey and black. Not white and black.
White field
Mid-grey field
Black field
Not a photograph. All three patches are offset from their background by exactly the same amount. Wind the slider down until two of them disappear: on most panels the grey one is the last still visible, often by a long way. A retained image is precisely this kind of small, even offset, which is why the burn-in test starts on grey and why running only a white field misses so much. If your panel disagrees, that is worth telling me about.
Last checked 2026-08-04
A tint on one primary is the input chain, not the panel.
Red looking orange or blue looking purple almost always traces upstream. Check RGB range (Limited against Full) between GPU and monitor, the monitor picture preset, any ICC profile, and the cable if you are running high refresh.
Panels that genuinely lose a channel tend to fail obviously rather than subtly.
What this test cannot tell you.
Solid fields say nothing at all about:
•Response time, ghosting, and overshoot
•Actual refresh rate and frame pacing
•Gamma curve accuracy
•Absolute colour accuracy, which needs a colorimeter
•Flicker from PWM backlight dimming
Written by Mor. If a panel of yours behaves differently, tell me and I will correct it.
Other tools
White Screen Test Check a white field for dust, dead pixels, uniformity, and tint.
Dead Pixel Test Cycle white, black, red, green, and blue to find faulty pixels.
Stuck Pixel Fixer Rapidly flash colors over a stuck pixel to try to un-stick it.
Backlight Bleed Test Spot light leaking around the edges of an LCD panel on black.
Screen Burn-In Test Reveal retained images and uneven wear on OLED and plasma panels.
Light Box Use the screen as a tracing panel or soft photography light.