Dead Pixel Test & Stuck Pixel Fixer

How to use the dead pixel test

1. Clean the screen with a soft, dry microfiber cloth. Dust and smudges look a lot like dead pixels.
2. Set brightness to maximum and, if you can, dim the room lights.
3. Press "Start dead pixel test". The screen fills with one solid color at a time.
4. Scan the whole screen slowly on each color, including the corners and edges. Look from a normal viewing distance first, then up close.
5. Note what you find: the position and which colors show the problem. That tells you what kind of pixel fault you have (see below).

On phones, turn the device sideways to see more of the screen at once. On iPhone, Safari can't hide the address bar completely, so scroll it away or check the area behind it on a second pass.

Dead, stuck or hot pixel? How to tell

Every pixel is made of three small sub-pixels: red, green and blue. Which colors show a fault tells you what is wrong:

• Dead pixel – a black dot that stays black on every color, most obvious on the white screen. The pixel gets no power. Usually permanent.
• Stuck pixel – a red, green, blue (or mixed-color) dot, most obvious on the black screen. One or more sub-pixels are locked on. Often fixable.
• Hot pixel – a white dot on the black screen: all three sub-pixels are stuck on. Sometimes fixable.
• Dust or a scratch – a spot that looks the same on every color and moves or looks blurry when you change your viewing angle. Clean the screen and test again.

How the stuck pixel fixer works

The stuck pixel fixer flashes red, green, blue, white and black many times per second. Switching a stuck sub-pixel on and off very quickly can sometimes get it working normally again. It works best on pixels that became stuck recently.

1. Run the dead pixel test and note where the stuck pixel is.
2. Tick the warning box, choose a box size and press Start stuck pixel fixer.
3. Drag the flashing box over the stuck pixel, or choose Whole screen if you aren't sure where it is.
4. Leave it running for 10–20 minutes and look away while it flashes.
5. Press Esc or the ✕ button, then run the dead pixel test again. Repeat a few times if the pixel looks different but isn't fully fixed.

If the pixel hasn't changed after two or three long runs, it is probably a hardware fault. Some people try gently massaging the spot through a soft cloth while the fixer runs, but pressing on a screen can make things worse, so we don't recommend it on laptops, phones or OLED panels.

What about OLED screens?

OLED phones and TVs can show a different problem called burn-in: a faint permanent image of something that was on screen for a long time, like a status bar or a TV channel logo. The gray screen in this test is the easiest way to spot it. Burn-in isn't a stuck pixel, and the fixer won't remove it.

Checking a new monitor or laptop

Run this test as soon as you unpack a new screen. Many manufacturers have a pixel policy that only covers a screen once it has a certain number of faulty pixels, so a single dead pixel may not be covered by the warranty. A store's return window, on the other hand, usually lets you return the screen for any reason, so finding a problem in the first few days matters.

How we tested this tool

We checked the dead pixel test and the stuck pixel fixer in Google Chrome on Windows and in a mobile-size browser view, making sure each color fills the entire screen with no borders, that keyboard and tap controls work, and that the fixer box can be dragged. Have you used it on your own device? Tell us how it went and we'll add your results here.

Frequently asked questions