Before you start
The dead pixel vs stuck pixel question is settled by one colour sweep, but only if you can see the pixel. Get close enough to see individual pixels, which for a typical desktop monitor means around thirty centimetres. At normal viewing distance a single defective pixel is often invisible, and you will spend twenty minutes chasing something you cannot reliably locate.
Clean the panel first. Dust, dried spray and skin oil all masquerade as pixel defects, and a dry microfibre cloth eliminates the most common false positive in about ten seconds.
Set browser zoom to 100% and enter fullscreen so no interface element sits over the field. Anything drawn on top of the test pattern makes an accurate judgement impossible.
Run the check
Display a white field and note every point that appears dark. White drives every subpixel to maximum, so anything not lit is a candidate. Mark the position rather than trusting memory; the screen test stores marks as normalised coordinates so they survive a resize.
Display a black field and note every point that appears bright. Black drives every subpixel to zero, so anything glowing is a candidate on the opposite side of the same question.
Now sweep red, green and blue in turn. This is the step most people skip and it is the one that produces the answer: a pixel that appears wrong on all three primaries behaves differently from one that appears wrong on only a single primary.
Cross-reference the three lists, because this is where dead pixel vs stuck pixel is actually decided. A point that appeared dark on white and stayed dark on every primary is dead. A point that appeared bright on black and stays bright on every field is stuck. A point that only misbehaves on one primary has one failed subpixel while the other two work.
Read your result
A dead pixel receives no power at all, so it stays black regardless of what is displayed. It is permanent, no software can revive it, and it is the case with the strongest claim to a warranty replacement.
A stuck pixel is powered but locked on a value, so it stays red, green, blue or white on every field. Because the transistor is still working, rapid colour cycling occasionally frees it, which is why pixel refresher patterns exist and are worth a try before anything else.
A single failed subpixel is the middle case: the pixel still displays most colours acceptably and only looks wrong when its failed component should be active. Many pixel policies count subpixels separately, so this affects the threshold for a claim.
Measurement limits
A browser cannot address individual pixels with certainty. Operating-system scaling, browser zoom, panel overdrive and colour management all sit between the page and the panel, which is why the instruction to reset zoom and enter fullscreen is not optional.
The colour cycling used by pixel refreshers is not the panel's own maintenance routine. Displaying colours quickly in a browser sometimes unsticks a pixel, but it does not run the firmware compensation cycle that OLED panels perform for image retention.
Nothing observed here can predict whether a stuck pixel will return. Freed pixels sometimes re-stick after hours or days, so a successful refresh is not a permanent conclusion.
What to do next
For a stuck pixel, run a colour cycle for twenty to thirty minutes before doing anything else. It is free, it works some of the time, and it costs nothing if it does not. Gentle pressure techniques circulate widely but risk permanent damage and are not worth it.
For a dead pixel, go straight to the manufacturer's pixel policy and count what you have. Dead pixels do not recover, so time spent on refresh cycles is time the return window is closing.
For a subpixel fault, check whether the policy counts subpixels or whole pixels. That single detail frequently decides whether a claim will succeed, and it is worth reading before you make the call.
Symptom table
| Symptom | Likely layer | Next action |
|---|---|---|
| Black point on white field | Dead pixel or contamination | Clean, then confirm across all primaries |
| Coloured point on black field | Stuck pixel locked on a value | Run a colour cycle for twenty minutes |
| Fault on green only | One failed subpixel | Check whether the policy counts subpixels |
Common questions
What is the difference between a dead and a stuck pixel?
A dead pixel receives no power and stays black on every colour. A stuck pixel is powered but locked on one value and stays bright on every colour. Stuck pixels can sometimes be freed; dead pixels cannot.
Can a stuck pixel fix itself?
Sometimes. Rapid colour cycling for twenty to thirty minutes frees a proportion of stuck pixels, and some resolve on their own over days. It is worth trying before starting a warranty process.
Should I press on a stuck pixel to fix it?
No. Pressure techniques circulate widely but risk permanently damaging the layers beneath and can turn a single stuck pixel into a much larger defect. Colour cycling carries no such risk.