🟥 Dead Pixel Test
Check a monitor, laptop, TV or phone for dead, stuck or hot pixels and backlight bleed with full-screen solid colors. Keyboard and tap controls.
Clean the screen first — dust looks just like a dead pixel. Then start the test and look closely at every part of the display on each color.
Next color: click, tap, Space or →. Previous: ←. Hide the hint: H. Exit: Esc (or the ✕ button).
Colors in the test
What Dead Pixel Test Does
This dead pixel test fills your screen with one solid color at a time — black, white, red, green, blue, gray, cyan, magenta and yellow — so faulty pixels have nowhere to hide. Step through the colors with a click, tap, the spacebar or the arrow keys, or let them cycle automatically every three seconds. It works on monitors, laptops, TVs with a browser, tablets and phones.
Each color reveals something different: black shows hot or stuck pixels that stay lit, white shows dead pixels that stay dark, the pure red, green and blue screens show a subpixel stuck on or off, and gray reveals uneven backlighting, clouding and banding. The test uses steady colors only — no rapid flashing — because flashing patterns can trigger seizures in people with photosensitive epilepsy.
How to Use Dead Pixel Test
- Clean the screen so dust is not mistaken for a pixel
- Press Start full-screen test
- Look closely at the whole screen on each color
- Press Space, click or tap for the next color; Esc to exit
- Note any dots that stay dark, colored or bright
What You Might See
| Fault | Looks like | Best screen to spot it |
|---|---|---|
| Dead pixel | A tiny dot that never lights | White |
| Stuck pixel | A dot fixed at red, green or blue | Black, and the other two primary colors |
| Hot pixel | A dot that is always bright white | Black |
| Backlight bleed | Light leaking from edges or corners | Black, in a dark room |
| Clouding / mura | Patchy, uneven brightness | Gray and black |
| Dust or debris | A dot that moves or wipes away | Any — clean the screen first |
How to Read Your Result
Check before the return window closes
Test a new monitor, laptop or phone on the first day. Manufacturers and retailers set their own pixel policies — some replace a display for a single bright pixel, others only above a count or within a central zone — and many policies apply only for a limited time after purchase.
Stuck vs dead
A stuck pixel is a subpixel receiving power when it should not, and it sometimes recovers on its own after hours or days of normal use. A dead pixel has a failed transistor and almost never comes back. If a dot changes color between test screens, it is stuck rather than dead.
Limitations & Accuracy Notes
- Very high-density screens make single pixels hard to see; look closely, or use a magnifier.
- iPhone Safari may not allow true full screen; the colors still cover the page.
- The test cannot repair pixels.