Dead pixel test
Fill your screen with solid red, green, blue, white and black to hunt for dead or stuck pixels on any monitor, laptop or phone. No download or permission needed, and nothing ever leaves your browser.
Dead pixel test
Enter fullscreen and cycle through solid colors to spot dead or stuck pixels. Click / tap or press → for the next color, ← for the previous, and Esc to exit. Swipe left/right on touch screens.
Colors used
100% local — nothing leaves your device
How to use it
- 1 Press the button to go full screen and clean your screen first so dust isn't mistaken for a fault.
- 2 Tap or click (or use arrow keys) to cycle through each solid color: red, green, blue, white and black.
- 3 Look closely for any dot that stays the wrong color or stays black across every screen.
- 4 Press Esc or the exit button to leave full screen when you're done.
Troubleshooting
Dead pixel test won't go full screen in Chrome
Full screen needs a direct click or key press, so it can't trigger automatically. Press the start button yourself rather than relying on a script, allow full screen if the browser asks, and exit any kiosk extension. If F11 is blocked, the on-page full-screen button still works in Chrome, Edge and Firefox.
Found a dead pixel test spot on Windows 11 — is it dead or stuck?
A dead pixel stays black on every color screen because it gets no power. A stuck pixel shows a fixed red, green or blue dot since one sub-pixel is locked on. Stuck pixels sometimes recover; truly dead ones do not. Cycle all colors to tell them apart.
Black spots appear on white but vanish on dark screens
Those are almost always dust or smudges, not pixel faults. A real dead pixel stays in the exact same spot on every solid color. Turn off full screen, wipe the panel gently with a dry microfiber cloth, then rerun the test before assuming the screen is damaged.
Dead pixel test not working on Android or iPhone
On mobile the Fullscreen API is limited, so the page may show a near-full-screen color instead of true full screen. Hide the browser toolbar by scrolling, turn auto-brightness off, and tap to change colors. Rotate the phone to check edges, since faults often hide near the corners.
Frequently asked questions
Is anything uploaded or recorded during the test?
No. The tool only paints solid colors on your screen using your browser. There is no camera, no upload and no tracking of what you find — everything runs locally on your device.
What's the difference between a dead pixel and a stuck pixel?
A dead pixel receives no power and stays black on every color, while a stuck pixel has one sub-pixel locked on and shows a constant red, green or blue dot. Stuck pixels can sometimes be revived; dead pixels usually cannot.
How do I check a used monitor or phone for dead pixels?
Open this test on the device, go full screen and cycle through every solid color. Dead pixels appear as black dots and stuck pixels as colored dots that stay in the same place. Always check the corners and edges where faults are easy to miss.
Can I fix a stuck pixel after finding one?
Sometimes. Rapidly flashing colors or gently massaging the spot through a cloth can occasionally unstick a sub-pixel. Dead (black) pixels get no power and generally can't be fixed in software.
Which browsers and devices does it work on?
It works in any modern browser — Chrome, Edge, Firefox, Safari and Opera — on Windows, Mac, Linux, Android and iOS. Desktop browsers give true full screen; mobile browsers may show a near-full-screen color instead.
How many dead pixels are normal or acceptable?
Most makers allow a small number under their warranty before replacing a panel, and the exact limit varies by brand and screen class. Check the manufacturer's dead-pixel policy, since a single fault often isn't covered.