Display Tests

Cycle full-screen solid colors to spot dead or stuck pixels. Keyboard, click or swipe to change color.

Estimate how many times per second your display updates by sampling animation frames, with confidence and background-tab detection.

Flash rapidly cycling colors over a stuck pixel to try to revive it. Includes a seizure warning, safe speed limits and auto-stop.

Read your CSS viewport, available screen size, device pixel ratio and orientation, with a browser-zoom hint.

Ishihara-style plates that hint at red-green color vision differences. A for-fun, non-medical screening that depends on your screen.

Cycle colors and moving patterns full-screen to help even out OLED image retention. May reduce mild retention; can’t fix permanent burn-in.

Full-screen primary, secondary and grayscale fields with labels to inspect color reproduction.

Monitor browser rendering frame rate with a frame-time graph and dropped-frame count. Distinct from monitor refresh rate.

Marching bars that step one pixel per frame reveal skipped frames as stutter or doubling — best judged with a phone camera photo.

Vary the rendering cadence on a gray field to watch for the brightness flicker some FreeSync/G-Sync displays show. Browsers can’t confirm VRR.

Track a moving object at adjustable speeds and backgrounds to inspect motion blur and ghosting. A visual check, not a millisecond measurement.

See whether your browser reports high dynamic range support via the dynamic-range media queries.

Inspect numbered near-black patches full-screen to check shadow detail and whether your display crushes blacks.

Check whether your browser reports sRGB, Display P3 or Rec. 2020 gamut coverage for this display.

Inspect numbered near-white patches full-screen to check highlight detail and whether your display clips whites.

Check pure black against pure white and a fine high-contrast checkerboard to inspect your display’s contrast.

View single-pixel line grids and small text full-screen to spot scaling, blur or non-native resolution issues.

Match a dithered line pattern against gray patches to estimate your display’s gamma. A rough visual check, not a calibration.

Smooth horizontal and vertical gradients to inspect banding, in grayscale and color.

Read the color and pixel depth your browser reports, with a note on why it may differ from the panel’s native depth.

See your current viewport and screen aspect ratios, and calculate any custom width/height ratio.

Enter and exit fullscreen, read the detected dimensions, and confirm the Escape flow works.