Screen Test
A fullscreen sweep with 8 solid colors, 50% gray and gradients to locate dead pixels, stuck pixels, backlight bleed and banding on your monitor or laptop. Navigate with click, arrows or Space; Esc exits. Nothing to install.
What to look for on each screen
On solid colors, a permanent black dot over white (or white over black) is a dead pixel; a colored one is a stuck pixel. The 50% gray and the gradients reveal backlight bleed (brighter corners), banding and panel uniformity. Clean the screen first: dust plays tricks.
Built by
Miguel Ángel Colorado Marin (MACM)
Built by
Miguel Ángel Colorado Marin (MACM)
Full-Stack Developer · Guadalajara, España
I develop web apps, digital tools and full projects — from design to deployment.
A dead pixel doesn't show up watching videos: it hides on flat solid screens. This test runs the classic pattern on your monitor — 8 solid colors fullscreen, uniform 50% gray and gradients — to locate dead pixels, stuck pixels, backlight bleed and banding. The sweep goes native fullscreen with controls that hide themselves after 2.5 seconds; advance with click, arrow keys or Space, right-click goes back. It's the test to run on a brand-new laptop inside the return window, and the first thing support asks for when claiming a defective panel.
Features
- ✓8 fullscreen solid colors: black, white, RGB primaries and secondaries
- ✓50% gray plus horizontal and vertical gradients for bleed and banding
- ✓Native fullscreen with auto-hiding controls
- ✓Navigate with click (next), right-click (previous), ← → and Space
- ✓Per-defect guidance with nothing to install
How to find dead pixels?
- 1
Clean the screen and go fullscreen
Dust and fingerprints mimic dead pixels; fullscreen removes window edges.
- 2
Sweep the colors
Advance with →: on white look for black dots (dead), on black look for colored dots (stuck).
- 3
Check gray and gradients
The 50% gray and gradients show light bleed and color bands — turn the room lights off.
- 4
Note the defects
Photograph defects with your phone: that's your warranty or return evidence.
Frequently asked questions
What's the difference between a dead pixel and a stuck pixel?
A dead pixel is off: permanently black on every screen. A stuck pixel always shows the same color. Stuck ones sometimes recover with rapid color-cycling tools; dead ones rarely do. Many warranties require 3-7 dead pixels before replacement — check yours.
Can the test fix a stuck pixel?
This test detects, it doesn't repair. Pixel-reviver tools cycle colors thousands of times and sometimes work on LCDs, never on OLED or mini-LED. The honest path: if defects show up, the test gives you the evidence for warranty or return.
Why does finding dead pixels need fullscreen?
Window edges, scrollbars and UI elements create light and dark spots that mimic defects. Fullscreen makes the color 100% uniform: any pixel that doesn't change with the sweep is a real panel defect, not a web element.
Related tools
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