Free Dead Pixel Test
Dead Pixel Test fills your screen with solid colors, gradients, gray uniformity screens and a checkerboard of single physical pixels, so dead (black) and stuck (colored) pixels stand out. Step through them with a click, Space or the right arrow. A flashing fixer for stuck pixels sits behind a photosensitivity warning and is not guaranteed to work.
- Screens:
- 9 solid colors and 9 patterns
- Checkerboard:
- 1 physical pixel per square
- iPhone:
- Fills the visible window only
- Price:
- Free
- Runs:
- Locally, in your browser
- Uploads:
- None: files never leave your device
- Account:
- Not needed
Quick answers
What's the difference between a dead and a stuck pixel?
A dead pixel stays black on every color because it gets no power. A stuck pixel stays lit in one color (red, green, blue or white). Stuck pixels can sometimes recover; dead pixels usually can't.
Can the stuck pixel fixer really repair my screen?
Sometimes. Rapidly cycling colors over a stuck pixel for 10–20 minutes occasionally frees it, but there's no guarantee and it cannot fix dead pixels or cracks. Never use it if you are sensitive to flashing lights.
Processed on your device: your files are never uploaded. How it works
Network activity in this tab
What this page has requested since you opened the site in this tab. An upload is any request that sends data: POST, PUT, PATCH or a request with a body.
No uploads: nothing has been sent from this page.
No network requests yet.
To see every request, open your browser's developer tools (Network tab).
How to use the Dead Pixel Test
- Clean your screen and press Start full-screen test.
- Click, press Space or the right arrow to step through the colors and patterns; look for dots that don't match.
- Press Esc to exit. Note where any dead (black) or stuck (colored) pixels are.
- For a stuck pixel, you can try the flashing fixer after reading the photosensitivity warning.
Credits & open source
Built from scratch on web standards. Thank you to the people who make these projects.
Web platform APIs used: Fullscreen API, Canvas 2D, Pointer Events.
Full license texts: third-party notices · all credits
Frequently asked questions
How many dead pixels are acceptable?
It depends on the manufacturer's pixel policy (often based on ISO 9241-307 classes). Check your warranty terms and test a new screen as soon as you get it.
Does it work on phones and TVs?
Yes, open the page in the device's browser. On iPhone the browser can't hide all toolbars, so the test fills the visible window instead of the whole screen.