Short answer: Fill your screen with solid white, black, and primary colors in fullscreen, then look for dots that never change. A dead pixel stays dark on white; a stuck pixel glows on black.
Most display problems are easier to catch on a flat color than on a busy desktop wallpaper. TestMyGears runs entirely in your browser, so you can check a new monitor during the return window without installing anything.
What counts as a pixel defect?
| Symptom on screen | Likely issue | Color that exposes it |
|---|---|---|
| Tiny dark speck on a bright background | Dead pixel | White screen |
| Bright dot on a dark background | Stuck or hot pixel | Black screen |
| Wrong tint on one color only | Sub-pixel fault | Matching red, green, or blue |
| Smudge that moves when you wipe | Dust, not a pixel | Clean first |
LCD panels use three sub-pixels per dot. That is why a fault might only appear on one of the RGB tests.
Five-minute test routine
- Lower the room lights. Glare hides small defects.
- Set browser zoom to 100%. Scaled pages leave untested borders.
- Open the white screen in fullscreen for 30–45 seconds. Sweep your eyes left to right, row by row.
- Switch to black. Stuck pixels often show up here first.
- Run red, green, and blue for 20–30 seconds each.
- Check corners and bezels — laptop and phone edges fail more often than the center.
- Repeat once if you are unsure. Real defects stay in the same spot.
Want hands-free cycling? The display tests pixel mode rotates colors every five seconds.
Get trustworthy results
- Wipe the panel before testing. A fleck of dust can look like a dead pixel in photos.
- Plug in laptops so brightness does not drop mid-test.
- On OLED phones, also glance at a grey screen for uneven glow at near-black levels.
- Take a photo of any defect with the test color still on screen — useful for warranty claims.
When a defect is worth reporting
Many brands allow one to three bright or dark sub-pixels before a replacement. Clusters, lines, or defects that spread across days are stronger cases. Note the date, color used, and location on the panel when you contact support.
Keep learning: Best colors for dead pixel tests · Fullscreen color test basics