Privacy first: All patterns are drawn locally in your browser. No screen image, screenshot or display data is uploaded.
Screen Test Tools tool
Choose a test pattern below or start the guided fullscreen sequence.
Display information
How to use the screen test patterns
Use solid colors to look for stuck or dead pixels, gradients to inspect banding, checkerboards and text to assess sharpness, and the moving boxes to observe ghosting or response-time artifacts.
- Clean the screen first so dust is not mistaken for a dead pixel.
- Inspect black, white, red, green and blue patterns in fullscreen mode.
- The refresh-rate estimate is based on browser animation timing and may differ slightly from the operating-system setting.
This visual test cannot repair pixels or certify display quality. Persistent defects should be checked against the manufacturer’s warranty policy.
Frequently Asked Questions
Can this tool fix a dead pixel?
No. It helps you visually identify possible dead or stuck pixels but cannot repair physical display defects.
Why is the refresh-rate estimate slightly different?
Browser scheduling, power saving, variable refresh rate and background processes can affect animation timing.
Which color is best for finding dead pixels?
Check all solid colors. Black and white reveal brightness defects, while red, green and blue help identify failed color subpixels.