A bad pixel hides fine against a busy desktop. Open a white document or a dark photo and it’s obvious: a tiny dot that won’t match the screen around it. Flood the display with a single solid color and it has nowhere to hide. This guide covers the browser test, the three pixel types, what you can actually fix, and when to return the screen.
Dead, stuck, or hot: know what you found
Not every bad pixel is the same, and the type tells you whether it is worth trying to save.
A dead pixel gets no power at all. It stays black on every color, so it shows up as a black speck on white, red, green, or any bright fill. A dead pixel almost never comes back.
A stuck pixel still gets power but it’s locked to one value. It glows red, green, or blue while the rest of the screen shows something else, and it stands out hardest against a black background. Stuck pixels are the ones with a real chance of recovery.
A hot pixel is rarer. All three subpixels fire at once and lock to white. It’s easier to spot than a dead pixel and harder to fix than a stuck one.
One more case. A pixel has three subpixels: red, green, and blue. Sometimes only one fails. That fault shows on one color and vanishes on the others. Cycling through the full set is the only way to catch it.
Run the dead pixel test
Start clean. Wipe the screen with a dry microfiber cloth first, because a speck of dust or a smudge looks a lot like a dead pixel and will send you chasing nothing.
Open the dead pixel test and go full screen so one solid color fills the whole display with nothing else on it. Click or use the arrow keys to step through the colors, or turn on Auto-cycle and let it rotate for you. On each fill, scan the whole screen slowly, corner to corner.
Get close. A single pixel is smaller than a grain of salt, so put your face near the glass or hold a phone camera up to the screen and zoom in. The black fill is where stuck and hot pixels give themselves away by glowing. The bright fills are where a dead pixel reads as a stubborn black dot. Work through white, red, green, and blue at minimum so a single-color subpixel fault has nowhere to hide.
Make sure it is really the screen
Before you treat a dot as a defect, rule out the easy explanations. Dust mimics dead pixels perfectly. Wipe the spot first, and if it’s gone, you never had a defect.
If it survives the cloth, check that the panel itself is at fault and not the signal feeding it. Plug into a different cable or port, or run the test on another device. A mark that follows the picture from one input to another is in the panel. A mark that disappears when you switch points at the cable or the graphics card instead, and that’s a much cheaper fix.
What you can actually fix
A stuck pixel sometimes recovers. A dead pixel almost never does, and no method reliably revives one. Put your time into the stuck ones.
The first method costs nothing and you already have it open. Run fast color changes over the stuck spot. Auto-cycle on the test does this for you, flipping the subpixel through colors fast enough to break the stuck state. Leave it running for 20 to 30 minutes before you call it.
If that does nothing, there is the pressure trick on an LCD. Power the screen off, fold a soft cloth over the exact spot, and press very gently for a few seconds while you turn it back on. Light pressure only. Push too hard and you trade one stuck pixel for a patch of dead ones.
One warning. Do not press on an OLED panel. OLED has no liquid crystal to reseat, and the surface scratches or cracks under pressure. On OLED, stick to the color-cycle method and leave the pressure alone.
Claim the warranty before the window closes
Most people skip this part and regret it. Manufacturers allow a set number of bad pixels before a panel counts as defective, and the limit follows the ISO 9241-307 standard. Under its common Class II, that’s up to 2 dead pixels and up to 5 stuck or partial ones per million. Some premium screens carry a zero bright dot guarantee that covers even a single stuck pixel. Your warranty spells out the exact count.
So test the moment a new monitor, laptop, or phone comes out of the box, while the return window is still open. Finding a dead pixel in week one is a free exchange. Finding it in month six is a fight. The same check pays off on a used display before money changes hands, where a hidden dead pixel is either a discount or a reason to walk.