Dead Pixel vs Stuck Pixel: How to Tell and How to Fix
One wrong dot on a new screen is maddening. Whether you can fix it, and whether the shop has to replace the screen, depends on which kind of dot it is.
The short answer
- A dead pixel is black on every colour: its transistor gets no power. It cannot be fixed by software.
- A stuck pixel is a bright red, green, blue or white dot: one sub-pixel is stuck on. These sometimes recover with a flashing-colour fixer or time.
- A hot pixel (white on black) is a stuck pixel with all three sub-pixels on. Dark smudges that move when pressed are dust or pressure marks, not pixels.
- Most makers follow ISO 9241-307 class II: a few defects per million pixels are "within spec". Premium zero-pixel policies and the retailer's own return window are your best route to a swap.
Try it in your browser
Dead Pixel TestCycle full-screen colours to spot dead or stuck pixels.First, find every bad pixel
Clean the screen with a dry microfibre cloth: most "dead pixels" reported to us turn out to be a speck of dust. Then run the dead pixel test full screen and step through black, white, red, green and blue. Look at each colour from about 30 cm, scanning in rows. Note what each dot does:
| On white | On black | On red, green, blue | What it is |
|---|---|---|---|
| Black dot | Invisible | Black dot | Dead pixel (all sub-pixels off). |
| Coloured dot (e.g. magenta) | Invisible | Black on one colour only | Dead sub-pixel: one of the three is off. |
| Invisible | Red, green or blue dot | Visible on the other two colours | Stuck sub-pixel: one is always on. |
| Invisible | White dot | Visible on every colour | Hot pixel: all three stuck on. |
| Grey smudge, often larger than a pixel | Invisible or faint | Faint | Pressure mark or mura, not a pixel defect. |
The test lets you mark where the dot is; it is anonymously added to the site map of where bad pixels sit. Most sit near the edges, where the panel is handled and flexed during assembly and shipping.
Why dead pixels stay dead
Each pixel on an LCD is three liquid-crystal cells (red, green, blue), each driven by its own thin-film transistor. When a transistor fails open, its cell never receives a charge, the crystal stays in its blocking state, and the sub-pixel is black no matter what the computer sends. On an OLED, a dead pixel is an emitter that no longer lights. There is no software path to a broken transistor, so a dead pixel is permanent. The only fix is a panel replacement.
The one exception: a cell that only looks dead because its transistor is stuck in a nearly-off state can occasionally be nudged by the same methods that help stuck pixels. It costs nothing to try, but do not expect much.
How to fix a stuck pixel
A stuck sub-pixel has a transistor that is passing charge when it should not, often because the liquid crystal in that cell has settled. Rapidly cycling the cell sometimes frees it. Success rates reported by users are around 30 to 50% for recently appeared stuck pixels and lower for old ones.
- Run the stuck pixel fixer over the dot for 10 to 20 minutes. It flashes the colours at high speed in a small window you drag over the pixel. Repeat two or three times; some pixels free up after an hour.
- Leave it running longer. A few hours of flashing colours or a full-screen colour cycle overnight is the next step. OLED owners should limit this to under an hour at a time.
- Gentle pressure (LCD only, at your own risk). Turn the screen off, wrap a fingertip or a stylus tip in a microfibre cloth, press lightly exactly on the pixel for a few seconds, and turn the screen on while pressing. The idea is to redistribute the liquid crystal. Press too hard and you create more defects, so this is a last resort, and never on an OLED, which has no liquid crystal.
- Warmth. A warm (not hot) damp cloth in a sealed bag held on the spot for a minute, combined with the fixer, is a folk remedy with occasional success.
If the pixel is still stuck after a couple of days of trying, it is unlikely to change.
Does one dead pixel qualify for a warranty replacement?
Usually not on its own, which surprises people. Panels are made with millions of transistors, and makers accept a few failures as normal. Most follow the ISO 9241-307 standard, where class II (the common class) allows per million pixels: up to 2 fully bright pixels, 2 fully dark pixels and 5 stuck sub-pixels. A 4K screen has 8.3 million pixels, so class II permits up to 16 bright, 16 dark and 41 sub-pixel defects. Many makers set stricter internal limits, especially for premium lines, and some add a rule about clusters (two defects within 5 mm) or dead pixels in the centre.
What actually works:
- Use the retailer's return window first. In the first 14 to 30 days most shops take a return for any reason; a dead pixel on day 3 is a return, not a warranty claim.
- Check for a zero-pixel policy. Some brands (Dell Premium Panel Guarantee, EIZO, some ASUS ProArt and LG lines) replace for a single bright pixel. The policy is in the warranty document for your exact model.
- Photograph it. A clear photo of the pixel on a white screen and on a black screen, with the model and serial visible in another photo, makes the claim simple.
- Phones and laptops are usually judged by the same standards; Apple, for instance, has an internal threshold that is not published but is known to replace for a small number of bright pixels under AppleCare.
Preventing pixel defects
You cannot prevent a transistor failing, but most defects after purchase come from physical stress: pressing on the screen to clean it, closing a laptop on a pen or earphone, or carrying a laptop in a bag that flexes the lid. Clean with a dry microfibre cloth and no pressure, keep anything hard off the keyboard before closing the lid, and use a sleeve with a stiff back. Run a quick pixel check on any new screen, used or new, within the return window; it takes two minutes.