Monitor & Dead Pixel Test
Pick a test screen below, then look closely across the whole display for pixels that don't change color, patches of uneven brightness, or visible color banding.
Click anywhere on the test screen to jump to the next one. Arrow keys and Esc also work.
This test displays full-screen colors and patterns so you can visually check for dead or stuck pixels, uneven brightness (backlight bleed) or color banding. It cannot measure objective specs like response time, contrast ratio or actual refresh rate — those require dedicated hardware. What you see also depends on your browser's color management, OS display settings and panel calibration, not only the screen itself.
What each screen is for
| Screen | What you can check | What a problem looks like |
|---|---|---|
| White | Dark spots on a light background, dust and uneven brightness | Black or dark dots; darker or tinted patches |
| Black | Bright dots and light escaping at the edges, best judged in a dim room | White or coloured dots that stay lit; a glow at the edges or corners (backlight bleed on LCD panels) |
| Red, Green, Blue | Dots and tints that a single colour can reveal | A dot that doesn't match the colour around it; a patch with a different shade |
| Gray | Even shading across a mid-tone screen | Lighter, darker or blotchy patches |
| Gradient | A smooth run from black to white | Visible bands or steps instead of a smooth transition (colour banding) |
| Checkerboard | Clean, even black and white squares | Blurred, uneven or shimmering edges, which can point to a scaling or display-mode setting |
Using the controls
Pick a tile to open a screen over the whole window. Click anywhere on it, use Next and Previous, or press the right and left arrow keys to move between the eight screens. Fullscreen fills the display, and Esc or Exit closes the test. A dark control bar stays along the bottom edge while a screen is shown, so a pixel hidden under that strip can't be judged here.
For uniformity, banding and backlight checks, work in a dim room at your usual brightness and turn off any night-light or colour-filter feature, so the patterns show plain colours.
Telling one problem from another
Three things are easy to confuse. A dot that always stays dark or always stays lit is a pixel problem; a speck that moves or wipes away is dust on the surface. Backlight bleed and banding are different again: they affect the whole panel rather than one dot, and they show best on the black and gradient screens. Because you do the inspecting, note where and on which colour you saw anything.
The guide on checking a monitor for dead and stuck pixels covers how to tell pixel defects from dust, what to write down and how to approach the seller or manufacturer, and why you shouldn't press on the screen.
What this test can't tell you
It only shows patterns: it doesn't count defects, classify them or judge whether they are acceptable. It can't measure response time, contrast ratio, colour accuracy or the real refresh rate, which need dedicated hardware. What you see is also shaped by your browser's colour management, your operating system's display settings and the panel's calibration, and manufacturers set their own policies on how many defective pixels they accept, so the seller or manufacturer decides what counts as a fault.
What to do next
If you find a defect, read the pixel guide before contacting anyone. If the picture looks fine but motion doesn't feel as smooth as the monitor should allow, the Refresh Rate Test estimates how often your browser draws frames, and the Reaction Time Test shows how your screen and input device behave in a timed response.
Related guides
How to Check a Monitor for Dead and Stuck Pixels — and What to Do If You Find One
Check a monitor for dead and stuck pixels with TryYourGear's Monitor Test, tell them apart from dust, document the defect and check your manufacturer's policy.
Read guideWhat a Browser-Based Hardware Test Can and Can't Measure
How TryYourGear's 12 browser tests work: what each observes, what it can't measure and what result it gives, from key codes to refresh rate and latency.
Read guide