Three kinds of bad pixels — identify yours first
Each pixel is made of red, green, and blue subpixels, and what you can do about a bad one depends on its type. A dead pixel has lost its electrical connection and stays black on every color. A stuck pixel has a subpixel frozen on — visible as a red, green, or blue dot on a black screen. A hot pixel glows white all the time.
Our monitor test's full-screen check tells them apart in under a minute: a black dot on the white screen is dead, a colored dot on the black screen is stuck, and a dot visible only on one of the R/G/B screens is a single failed subpixel. Wipe the screen first — dust masquerading as a dead pixel is remarkably common.
Warranty rules: stricter than you'd expect
Most people assume one bad pixel means a free replacement. Most manufacturer policies say otherwise: they typically distinguish bright defects (stuck/hot) from dark ones (dead) and require something like 'N bright, M dark, or K total' before a panel qualifies — some even weigh the pixel's position, with stricter thresholds near the center. This is exactly why some brands sell zero-bright-dot guarantees as a separate premium.
So before buying, check two things: the pixel policy for that specific brand and model (in the official warranty terms), and your retailer's DOA/early-return window — often just days after unboxing. Testing the monitor with our tool on delivery day, photographing any defect, and filing within the window is the only reliable defense.
Which pixels can be revived
Stuck pixels are liquid-crystal molecules jammed in one state, so recovery is possible: running a pixel-refresh utility that flashes rapid colors over the spot for a few hours sometimes works, as does very gentle pressure through a soft cloth (never press hard — you can damage the panel). A real fraction of stuck pixels do come back.
Dead pixels, by contrast, have a broken electrical connection and no software can resurrect them. If your test shows a dead pixel, don't burn days on revival tricks — spend that time checking whether you meet the exchange threshold and whether your return window is still open. If a stuck pixel hasn't recovered after a few days of trying, move on to the policy check too.
Inspecting new and second-hand screens
Inspect a new monitor the day it arrives, before you finish setting it up. Two full laps of the five-color full-screen cycle, scanning corner to corner, takes about two minutes. Miss the early-return window and the very same defect may fall under the ordinary pixel policy — where it might not qualify at all.
For second-hand deals, test on the seller's screen before money changes hands. Meeting up for a used laptop or monitor? Open this site right there and run the dead-pixel check and refresh-rate measurement — nothing to install, done in a minute or two with the seller's consent, and any defect you find is honest leverage on the price.