How to test for dead pixels
- Clean your screen with a soft cloth — dust and smudges mimic dead pixels.
- Start the full-screen test and step through every color. Dead and stuck pixels only show up against certain backgrounds, so don't skip any.
- Look closely, especially on the solid white screen (reveals dead/black pixels) and the solid black screen (reveals stuck/bright pixels).
- Found a stuck pixel? Press F or run the fixer over it for 10–20 minutes.
Dead vs. stuck vs. hot pixels
| Type | Looks like | Fixable? |
|---|---|---|
| Stuck pixel | Always one color (red, green or blue), even on black | Often — try the fixer |
| Dead pixel | Always black, even on white | Rarely — no power reaching it |
| Hot pixel | Always white/bright on black | Sometimes — try the fixer |
How the stuck-pixel fixer works
A stuck pixel has a sub-pixel frozen in one state. The fixer rapidly flashes random colors over the area, forcing those sub-pixels to switch on and off many times a second, which can free a stuck transistor. Run it for 10–20 minutes on the spot; gentle pressure with a soft, damp cloth while it runs sometimes helps. It won't revive a truly dead (black) pixel.
Checking a brand-new screen
Test any new monitor, laptop or phone immediately, while you're still inside the return window. Manufacturers grade panels under ISO 9241-307, and many will only replace a display once a threshold of dead sub-pixels is met — but if you're within the retailer's return period, a single annoying stuck pixel is often enough to swap the unit. Premium and professional monitors frequently carry a zero-bright-dot guarantee worth claiming.
Frequently asked questions
How do I test for dead pixels?
Run the test full-screen and cycle through black, white, red, green and blue. Any dot that doesn't match the background is a suspect — checking several colors is what exposes them.
Dead pixel vs. stuck pixel?
A stuck pixel is locked on in one color (often revivable); a dead pixel gets no power and stays black (usually not revivable in software).
Can stuck pixels be fixed?
Often — run the fixer over the spot for 10–20 minutes. Light pressure with a soft cloth while it flashes can help. Dead black pixels generally can't be revived.
How many dead pixels are normal?
Manufacturers set thresholds under ISO 9241-307, but if you're within the store's return window, even one stuck pixel is often grounds to swap a new unit. Test early.
Does it work on phones and TVs?
Yes — it's browser-based, so it works on phones, tablets, monitors and smart TVs. On a TV, open it in the TV browser or cast a full-screen tab.
More free tools
Testing the rest of your setup? Try the Gamepad Tester, Keyboard Tester and Mic Test · See all Alienated Tools.