What is the difference between a stuck pixel and a dead pixel?
A dead pixel stays dark on every colour because it receives no power. A stuck pixel stays lit on every colour, fixed at one value.
Each pixel is made of three subpixels — red, green and blue — and each subpixel has its own transistor. Apple describes the failure precisely: a transistor that does not work perfectly leaves the affected subpixel remaining off (dark) or on (bright). Off is what people call dead; on is what people call stuck.
That single difference explains everything else about them, including which background reveals which and why only one of the two ever recovers.
How do you tell a stuck pixel from a dead pixel?
Change the background. A dot that stays black on a white field is dead. A dot that stays coloured on a black field is stuck.
This is why testing on one colour is not enough. A dead pixel is invisible against black, because everything around it is black too. A stuck red subpixel is invisible against red. Cycling through white, black, red, green and blue catches both, which is exactly what the dead pixel test does.
A stuck pixel also has a colour: it will look red, green, blue, or a mix, depending on which subpixels are stuck on. A dead pixel has no colour at all.
Do stuck pixels go away on their own?
Sometimes, though nothing about this is reliable. The subpixel is still powered, so a latched transistor can occasionally settle back on its own.
We have not found a display manufacturer that publishes a recovery rate or endorses a method, so treat confident claims with suspicion. Rapid colour cycling over the affected area is the usual suggestion; it costs nothing and cannot damage anything, so it is a reasonable thing to try.
Applying pressure to the panel is also widely suggested. We would not: it risks permanently damaging the pixels around the one you are trying to fix, and pressure damage is generally treated as user damage rather than a warranty fault.
Can a dead pixel be repaired?
No. A dead pixel has no power reaching it, so there is nothing for colour cycling or any software method to act on.
This is the practical reason the distinction matters. Time spent running a pixel-fixing routine at a genuinely dead pixel is time wasted. Identify which one you have first, and if it is dead, the only remedies are a warranty claim or living with it.
Do stuck or dead pixels spread?
A single faulty transistor does not spread to its neighbours. A growing dark patch is usually physical damage instead, which does spread.
If a spot is getting larger over days or weeks, that points at panel damage — pressure, impact or liquid — rather than a transistor fault. That distinction matters for a warranty conversation, because physical damage is normally excluded.
Is a dark spot always a dead pixel?
No. Dust and other foreign material look very similar and are the single most common false positive, which is why cleaning the screen comes first.
Apple makes the same point: a small piece of dust or other foreign material may appear to be a pixel anomaly, and is typically irregular in shape and most noticeable against a white background.
Two quick tells. A real pixel fault is a perfect square with hard edges; dust is irregular. And a speck on the outside of the glass appears to shift as you change viewing angle, while a pixel fault never moves.
How many faulty pixels are normal?
A handful across millions is treated as normal manufacturing variation. Most manufacturers require several faults before a panel qualifies for replacement.
Apple notes that with millions of subpixels on a display it is possible to have a low number of imperfect transistors, and asks you to bring the device in for evaluation rather than publishing a public threshold. Policies vary by brand and by panel class, so check the warranty terms for your specific model rather than assuming a number from elsewhere.
One thing worth knowing when buying: bright stuck subpixels are often treated more strictly than dark ones, because they are more noticeable in normal use.
How do you check a screen for faulty pixels?
Clean the screen, go fullscreen, then step through white, black, red, green and blue looking for anything that does not change.
Run the dead pixel test, which cycles those fields for you. Follow it with the uniformity test if you are checking a new panel, since backlight bleed and clouding are separate faults that pixel testing will not reveal.