Dead Pixel Test Online
Cycle through eight full-screen colors to find dead pixels, stuck subpixels, and marks that only become visible on a uniform background. The test runs entirely in your browser.
Start with a clean screen
No download, account, or uploaded screen data required.
What this screen test can reveal
Dead pixels
Pixels that stay dark on white or primary-color screens can indicate a failed pixel or subpixel.
Stuck pixels
Bright red, green, blue, or white points that remain visible on black can indicate a subpixel stuck in the on state.
Subpixel defects
Red, green, and blue fields isolate each primary subpixel channel so small color failures are easier to locate.
Surface marks
Uniform colors make dust and smudges easier to find before you mistake them for panel damage.
How to run an accurate test
- 1
Clean the display
Use a dry microfiber cloth and remove reflections that could resemble pixel defects.
- 2
Open the full-screen test
Start with black, then inspect white and every primary color from a normal viewing distance.
- 3
Confirm the same location
A real defect remains in exactly the same place as the colors change. Recheck it at close range.
- 4
Record evidence
If the device is within its return period, photograph the defect on more than one test color and check the warranty policy.
Frequently asked questions
What is the difference between a dead pixel and a stuck pixel?
A dead pixel usually stays dark because it no longer produces light. A stuck pixel remains red, green, blue, or white. Solid-color screens help distinguish the two, but the test cannot determine whether a defect is covered by a manufacturer's policy.
Can dust look like a dead pixel?
Yes. Clean the screen gently before testing. Dust on the surface often changes appearance when viewed from an angle, while a pixel defect remains fixed within the image plane.
Does this test work on OLED, LCD, and LED screens?
Yes. The color sequence works on phones, tablets, laptops, monitors, and TVs. Defects may look different depending on the panel technology and pixel density.
Can an online test repair a dead pixel?
No. This tool is diagnostic. Rapid color cycling may sometimes affect a temporarily stuck subpixel, but it cannot repair a physically failed pixel and should not be presented as a guaranteed fix.