Home / Monitor Test
Monitor Test
Five test modules on one page: dead pixels, color ramps, grayscale, motion & refresh, and brightness uniformity. Test any monitor, laptop or TV before a return window closes — or before you buy used.
Dead pixel test
Full-screen solid colors rotate automatically every 2.5 seconds. A dead pixel stays black on every color; a stuck pixel stays red, green or blue while everything else changes. Watch for any dot that refuses to match the background.
How to read each monitor test
Dead pixel colors. The rotating solid colors isolate sub-pixel faults. Anything that stays black on all colors is a dead pixel; anything that keeps glowing on black is stuck. Note the location — warranty policies count defects.
Color ramps. The red, green and blue gradients from black should fade smoothly. Steps or stripes are banding: the panel can't reproduce every shade. Subtle banding is common; harsh stripes across all three ramps on a monitor that used to be clean point to a cable or GPU problem.
Grayscale. Each of the eight gray steps must be neutral — no pink, green or blue cast — and clearly distinct from its neighbors. A tint that appears only on some steps indicates a calibration fault; a tint on all of them means the panel or backlight is aging.
Motion & refresh. Track the moving square. On a 60 Hz office monitor a slight trail is normal; on a 144 Hz gaming monitor the square should look crisp. Dark-background smearing that light-background testing doesn't show is slow dark-pixel response — a VA panel trait.
Uniformity. Corners darker or cloudier than the center on flat gray mean uneven backlight distribution. Minor variation is universal; obvious cloudy patches (mura) justify an exchange on a new monitor.
Narrowing down a specific problem? Lines get a dedicated five-color diagnosis, edge glow has its own backlight bleed test, and single colors live on the color test hub.
Monitor test FAQ
How do I test my monitor for dead pixels?+
Open the Dead Pixels module above and let the full-screen colors rotate automatically. A dead pixel stays black on every color; a stuck pixel stays red, green, blue or white while the background changes.
What is a good monitor test sequence?+
Dead pixel colors first, then the black–white ramp for banding, the 8-step grayscale for tint and contrast, the motion test for response time, and finally the uniformity grays with brightness at maximum. Five minutes covers everything.
How do I test monitor refresh rate and response time?+
Follow the moving square in the Motion & Refresh module. A sharp square means fast pixel response; a trailing smear means slow response times (common on VA panels in dark scenes). Compare light and dark backgrounds.
My monitor shows color banding in the gradients. Is it broken?+
Visible steps in what should be a smooth ramp mean the panel or its driver is approximating colors — typical of 6-bit + FRC budget panels. It is a specification limit, not a fault you can repair. Banding that appears suddenly on a previously clean monitor suggests a failing cable or GPU output.
Does this monitor test work on laptops and TVs?+
Yes — anything with a browser. Laptops, external monitors, phones, tablets and smart TVs all render the same full-screen test patterns.