Screen Test Online
Verify your display's quality and detect any issues. ProbeCheck shows your screen resolution, pixel density, HDR support, wide color gamut (Display P3) detection, and offers a guided walkthrough that cycles through red, green, blue, white, black, gray, and gradient full-screen fills to identify dead or stuck pixels efficiently.
Browser PrecisionHigh
Resolution and pixel density from window.screen and devicePixelRatio. HDR via matchMedia.
Frequently Asked Questions
How do I check for dead pixels on my screen?
Use the guided walkthrough above, or pick any full-screen color test. Solid black, white, red, green, blue, gray, and gradient backgrounds make it easy to spot dead pixels (black dots on light colors) or stuck pixels (bright dots on dark colors). The walkthrough auto-advances every 10 seconds with tips for each color.
Does my monitor support HDR?
The HDR detection above checks if your browser and display report HDR capability using the dynamic-range media query. HDR also requires compatible OS settings, GPU drivers, and monitor firmware. Wide color gamut (Display P3) support is detected separately — many HDR monitors also support P3 for richer colors.
What is wide color gamut (Display P3)?
Wide color gamut displays can show more colors than standard sRGB screens. Display P3 is the most common wide gamut standard for consumer monitors. If your display supports P3, you'll see richer reds, greens, and more accurate skin tones in HDR content and supported apps.
What is my screen resolution?
Your current screen resolution and pixel density are displayed above. This includes the logical resolution, actual pixel dimensions (accounting for device pixel ratio), and color depth.