Dead Pixel Test
Clean the screen, switch through six full-screen solid colors, and mark the locations of fixed bright, dark, or stuck-color pixels.
Test settings
Solid-color output and location record
Choose a defect type first, then click the solid-color screen. Locations are saved as percentages of the screen width and height.
- No unusual locations marked yet.
- Bright
- 0
- Dark
- 0
- Stuck
- 0
- Current color
- White
- Colors reviewed
- 0/6
- Readiness
- 0/4
Review the same mark against several solid colors. Acceptable counts and warranty decisions depend on the relevant manufacturer's policy.
How to tell bright, dark, and stuck pixels apart
| Appearance | Typical look | How to confirm |
|---|---|---|
| Bright pixel | Stays bright on a black background; it may be a bright pixel or bright subpixel. | Switch through black, dark gray, and RGB colors to confirm that the location stays fixed. |
| Dark pixel | Stays dark on a white or bright background; it may be a dark pixel or dark subpixel. | Switch through white, gray, and RGB colors to rule out surface dust or an obstruction. |
| Stuck pixel | Stays red, green, blue, or another color and may be clearer on some backgrounds. | Check red, green, blue, and white in sequence to confirm that the unusual color does not change with the screen. |
| Dust or smudge | Usually has an irregular edge and may change with cleaning, viewing angle, or focus. | Turn the display off, clean the surface, change your viewing angle, and test again. |
Use and limitations
Test order and shortcuts
Start with white and black, then inspect red, green, blue, and gray. Slowly scan from the center toward the corners on each color. In full screen, use the left and right arrows for colors, 1/2/3 for bright, dark, and stuck marks, U to undo, C to clear, M to hide marks, H to hide controls, and F to exit.
How locations are recorded
Each mark is saved as a relative location: horizontal percentage = click x-coordinate ÷ test-screen width × 100%, and the vertical percentage is calculated the same way. The mark can return to the same relative position when the window changes size, but it is not a physical panel-pixel coordinate.
Scope and possible false observations
A web page cannot read the electrical state of each physical panel pixel or determine warranty eligibility automatically. Dust, protective films, browser or system zoom, subpixel structure, camera noise, and temporary image retention can affect observation. Recheck across several solid colors and the real viewing chain.
Privacy, sources, and license
All color changes, location marks, and summaries are completed locally in this browser. No screen content is uploaded, and the tool does not use the camera, microphone, or local storage. Full-screen and clipboard access are requested only after you choose those actions.
This tool is built with standalone HTML, CSS, and JavaScript and includes no third-party runtime library. Similar projects found during research informed feature boundaries only; their code and assets were not copied.
Frequently asked questions
Which colors should I check in a dead-pixel test?
Start with white and black, then inspect red, green, and blue, and finish with gray. Different backgrounds make bright, dark, and fixed-color defects easier to see.
How can I tell dust from a dead pixel?
Turn the display off and clean the surface first, then change your viewing angle. Dust and smudges often change with cleaning or perspective, while a physical pixel defect stays fixed on the panel.
Does one dead pixel automatically qualify for a warranty claim?
Not necessarily. Defect categories and acceptable counts vary by manufacturer, model, region, and warranty policy. Keep the location record and check the terms for the specific product.
Why cannot a screenshot show a physical dead pixel?
A screenshot stores the digital image generated by the system before it passes through the physical display panel, so a defect in the panel normally will not appear in the screenshot file.