Stuck Pixel Test

What a Stuck Pixel Is

Every pixel on your screen is made of three smaller lights: one red, one green and one blue. Mixing them at different strengths makes every colour you see. Turn all three on and you get white. Turn all three off and you get black.

A stuck pixel is one where some of those three have stopped changing. They are still lit, but they hold the same value no matter what the screen is showing. That is why a stuck pixel looks like a tiny red, green, blue, yellow or cyan dot sitting in the middle of the picture while everything around it moves.

This is worth separating from a dead pixel, because people use the two words for the same thing and they are not the same. A dead pixel is not lit at all. A stuck pixel is lit and wrong.

The difference matters for one reason: a stuck pixel is sometimes fixable and a dead one usually is not. The parts of a stuck pixel still work, they have just settled. Getting them to move again is what the fixer further down this page tries to do.

How to Fix a Stuck Pixel

Start with the honest part. A stuck pixel fix works sometimes. It is not a repair, there is no guarantee, and plenty of stuck pixels never come back no matter what you do. Anyone promising otherwise is selling something.

That said, the method below costs nothing and carries no risk, so it is worth ten minutes before you give up on the pixel or the screen.

The idea is simple. A stuck pixel has settled into one state. If you drive it through thousands of colour changes a minute, the parts inside it are being pushed hard in every direction, and sometimes that is enough to get one moving again. This is the method behind JScreenFix and every other tool of its kind, and it is what the fixer below does.

Run it for about ten minutes with the flashing area covering the stuck pixel, then stop and look at the spot on a black screen. If the dot has gone, you are done. If it is still there, one more run of ten or twenty minutes is reasonable, and after that the odds stop improving.

Two things worth knowing before you start. It has the best chance on an LCD, where a stuck pixel is usually a liquid crystal that has not moved. It has much less chance on a phone or any other OLED screen, where the pixel is its own light and a fault is more often the light itself failing.

And if the pixel comes back a few days later, that is normal. A pixel that unsticks once has a habit of sticking again, and there is nothing you can do about that beyond running the fixer again when it annoys you.

The Pressure Method, and Why to Leave It Alone

The other advice you will find is to press on the stuck pixel with a soft cloth while the screen is off, then switch it back on. It does work for some people, and it is worth explaining properly so you can decide for yourself.

Here is the problem with it. You are pushing on a panel with your finger and hoping you get the pressure right. Too hard, or in the wrong spot, and you can make more faulty pixels than you started with, leave a bruise-like mark that takes days to fade, or crack the panel outright. On a phone, a tablet or any OLED screen, do not do it at all.

So the sensible order is: run the flashing fixer first, since it cannot damage anything. Only think about pressure if the flashing has failed twice, the screen is an LCD, and you have decided you would rather risk the panel than live with the pixel.

If you do try it, the screen goes off first, the cloth is soft and clean, the pressure is gentle and on the pixel itself, and you switch the screen back on while still pressing. That is the whole method. Anything involving heat, cold, a hard object or a pen is worse advice than the pixel is a problem.

Stuck Pixel Test on an iPhone or Android Phone

The same test works on a phone, and you do not need an app for it. Open this page in Safari or Chrome, press the button, and the screen fills with the test colours exactly as it does on a monitor. Turn the brightness up first, because a dim screen hides a faint dot.

A stuck pixel test on an iPhone is worth running on a new one, on a refurbished one, and on any phone that has had its screen replaced. iOS has no pixel test of its own, so a browser page is the whole of it. There is nothing to install and nothing to pay for.

On Android it is the same, with one extra option. Many Samsung Galaxy phones have a hidden hardware test menu that you reach by typing *#0*# into the dialler. It includes plain red, green and blue screens, which is enough to check dead pixels on Android without leaving the phone. It is not on every model and other makers use different codes, so if nothing happens, use this page instead.

Whichever route you take, remember what a phone screen is. Almost every current phone is OLED, and on OLED a dot that never changes is more often a dead pixel or the start of burn-in than a stuck one. If the mark is a faint patch rather than a single sharp dot, look at the burn-in test rather than the fixer.

One last thing on phones: check a new one early. Screen faults are easiest to raise in the first days, and a phone you have owned for a year is a much harder conversation.

LCD and OLED Stuck Pixels

What sort of screen you have changes what a stuck pixel means and what you can do about it.

An LCD makes its picture by shining one backlight through a layer of liquid crystal. Each sub-pixel is a shutter that twists to let more or less light through. When one of those shutters stops twisting, it holds whatever it was showing, and you get a stuck pixel. Nothing is broken as such — a part has stopped moving. That is exactly the case where an LCD stuck pixel test followed by ten minutes of flashing has a real chance of working.

An OLED is different. There is no backlight and no shutter, and every pixel makes its own light. A pixel that has gone wrong on an OLED has usually had something fail rather than settle, and flashing colours at a failed light does not bring it back. OLED screens also age unevenly, which shows as a faint patch rather than a sharp dot.

So the short version: on a monitor or a laptop, which is almost certainly LCD, run the fixer. On a phone or a modern TV, which is probably OLED, run the test to find out what you have, but keep your expectations low about fixing it.

When a Stuck Pixel Is Worth Doing Something About

Not every stuck pixel needs acting on. One dot near a corner of a large monitor is something most people stop seeing within a week. A dot in the middle of the screen, or several together, is a different matter.

If the screen is new, this is worth raising straight away. Most manufacturers publish a policy on faulty pixels, and most of them will not replace a screen for a single one — there is usually a minimum number before a panel counts as faulty. The number is different for every maker, every product line and every country, so look up the policy for your exact model rather than trusting a number you read somewhere.

Retailers are often easier than manufacturers in the first weeks after a purchase, so if the screen is only days old, start with the shop.

It is also worth running this test before you buy something second hand, and before the return window closes on anything new. Two minutes on a black screen tells you what a seller will not.

And if the pixel is staying and the screen is out of warranty, it is fair to just let it go. A single stuck pixel does not spread, it does not damage anything else, and it does not get worse on its own.