Dead pixel test
Fill the screen with one solid colour at a time and look closely. A dead pixel stays black on every colour; a stuck pixel stays one colour while everything around it changes.
This test fills the whole screen with solid colours, and the optional cycling mode changes them rapidly. Rapid flashing can trigger a seizure in people with photosensitive epilepsy. Nothing starts until you choose to begin, and cycling is off by default.
Choose a colour to fill the screen. Press Escape, or click anywhere, to come back.
Dead, stuck, or dust
A dead pixel receives no power and stays black whatever is displayed. A stuck pixel is permanently lit in one colour — red, green or blue — and is most obvious against a black background. Dust on the outside of the panel moves when wiped; neither of the others will.
Why to check a new screen immediately
Manufacturers allow a number of faulty pixels before a panel counts as defective, and the thresholds are more generous than most buyers expect. A retailer return window is usually a far easier route than a warranty claim, and it closes quickly — checking on the day it arrives is worth the two minutes.
Nothing here leaves your device
Every one of these tests runs entirely in your browser using standard web APIs. No audio, video, keystroke or controller input is uploaded, recorded on a server, or stored anywhere — there is no upload endpoint for any of it to go to. Closing the tab discards everything.
Common questions
What is the difference between a dead and a stuck pixel?
A dead pixel is always black because it receives no power. A stuck pixel is permanently lit in a single colour. Stuck pixels sometimes recover; dead ones essentially never do.
Can a stuck pixel be fixed?
Sometimes. Rapidly cycling colours over the affected area can unstick it, and gentle pressure while the screen is on occasionally helps. Neither is guaranteed, and hard pressure will make things worse.