Monitor test
Check any screen for defects in a few minutes, right in the browser — dead pixels, ghosting, backlight bleed, uniformity problems, color banding, contrast, gamma, scaling sharpness, touch response, and your real refresh rate. Full-screen, free, nothing to install.
Screen tests
Dead pixel testCycle solid white, black, red, green, and blue to spot dead or stuck pixels.Backlight bleed testA pure black field shows where your LCD leaks light at the edges.Screen uniformity testGray fields reveal the dirty screen effect, vignetting, and tint shifts.Color banding testSmooth gradients expose visible steps in weak display pipelines.Contrast testStepped bands near black and white expose crushed shadows and clipped highlights.Gamma testStripe-vs-gray comparisons show whether your display hits the 2.2 standard.Sharpness testPixel-grid patterns reveal scaling blur, moiré, and TV processing.Refresh rate testMeasure the Hz your browser is really rendering, live.Ghosting testMoving blocks reveal trailing, smearing, and overdrive halos.Touch screen testPaint with your fingers to find dead zones and ghost touches.White screenA full-screen white field — dead pixels, tint checks, or a soft light.Black screenA full-screen black field — stuck pixels, bleed, and OLED blacks.
Display tools & calculators
Monitor testing FAQ
- How do I test a monitor for defects?
- Run the tests top to bottom: dead pixels first (solid colors), then backlight bleed (black field in a dim room), uniformity (gray fields), color banding (gradients), and finally the refresh rate check. The whole sequence takes about five minutes, and each test explains what a fault looks like.
- Should I test a brand-new monitor?
- Yes — immediately. Panel quality varies unit to unit even within a model, and most manufacturers only replace panels above a defect threshold. Testing within your return window means a bad panel is the seller's problem instead of yours.
- Do these tests work on phones and TVs?
- Yes. Everything here runs in the browser with no download, so any device with one works — phones and tablets included. For a TV, open this page in the TV's built-in browser, or plug in a laptop and mirror the screen.