How to use it
- Wipe the screen with a dry microfiber cloth first, so dust does not fool you.
- Press Start full screen. Click, tap or press the right arrow for the next color.
- Scan the whole screen slowly on each color, including the edges and corners. It helps to go row by row.
- When you spot a dot, turn on Mark a pixel (or press M) and click it. The ring stays as you change colors, and the panel lists its position.
Tiny dots are hard to see. Your phone camera zoomed in on the screen, or a magnifying glass, shows single pixels far better than the eye. A software magnifier cannot help here: it only enlarges the picture, not the physical pixel.
Dead, stuck or hot pixel?
| What you see | What it is |
|---|---|
| A black dot on every color, clearest on white | Dead pixel. The pixel never lights. |
| A red, green or blue dot that stays on, clearest on black | Stuck subpixel. One color of the pixel is always on. |
| A white dot that stays on, clearest on black | Hot pixel. All three colors are stuck on. |
| A dot missing one color, for example dark on red but fine on green and blue | Dead subpixel. One color of the pixel never lights. |
| A dot that moves or disappears when you wipe | Dust or a mark on the surface. |
Each pixel is made of red, green and blue subpixels, which is why the three primary colors matter: they show each subpixel on its own. Cyan, magenta and yellow light two at a time and help confirm which one is faulty.
What to do next
- Stuck or hot pixel: try the stuck pixel fixer. It flashes colors over the pixel and sometimes gets it working again. It is worth 10 to 30 minutes before you give up.
- Dead pixel: no software can fix a pixel that gets no power. Take a photo, note the position from your marks and contact the seller. Returns are easiest in the first days after you buy.
- Check the pixel policy: screen makers publish their own rules for how many faulty pixels count as a defect, and they differ. Some replace a screen for a single bright pixel, others need several.
Checking the rest of the screen too? The full screen test adds uniformity, backlight bleed, banding and more.
Questions
How do I know if I have a dead pixel?
Go through every color in full screen. A dot that stays black on every color is a dead pixel. A dot that stays red, green, blue or white is stuck. If it moves or goes away when you wipe the screen, it was dust.
Can a dead pixel fix itself?
A truly dead pixel rarely comes back. Stuck pixels sometimes do, on their own or with a pixel fixer.
Can dead pixels spread?
A single dead pixel does not usually spread. If new ones keep appearing over days or weeks, or you see lines, that points to a failing panel and is worth a warranty claim.
Does the dead pixel test work on phones and TVs?
Yes. It works in any modern browser. On a phone, tap to change color and use the close button to exit. On a TV, open the page in the TV browser or mirror a laptop.
What do the marked positions mean?
They are screen pixels counted from the top left corner, measured in full screen at 100% browser zoom. They are handy to quote to a seller, who can then find the same spot.