Dead Pixel Tester
Browser-based display utilities

Free Online Screen Testing Tools for Every Display

Test a display, create a clean background, light a video call or inspect your screen specifications. Every tool runs locally in your browser with no upload, account or install.

Color Screen

Open any solid color full screen or download it as an image.

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Screen Light

Turn your display into an adjustable warm or cool light source.

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Gradient Generator

Build, preview and export smooth two-color backgrounds.

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Screen Information

Inspect resolution, pixel density, viewport and display capabilities.

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Complete display test

45+ checks for pixels, gamma, uniformity, sharpness and motion.

Stuck pixel fixer

Exercise a stuck sub-pixel with a controlled RGB color cycle.

Solid color screens

Open a pure color fullscreen or download a ready-to-use AVIF background.

White ScreenBlack ScreenRed ScreenGreen ScreenBlue Screen

More screen experiments

Original browser experiments inspired by classic screensavers and broadcast screens.

AtmosphereWhite Noise→Prank screensBroken Screen→Prank screensHacker Typer→SimulationsFake Update→ScreensaversBouncing Logo→ScreensaversFlip Clock→ScreensaversDigital Rain→PatternsNo Signal→

Display diagnostics

Focused checks for panel uniformity, motion, color and HDR-era display behavior.

Backlight BleedUse a pure black field to inspect corner glow, clouding and IPS glow.GreyscaleScan a smooth set of neutral tones for crushed shadows, clipping and banding.Color AccuracyCompare a balanced reference palette across skin, foliage, sky and neutral swatches.Color GamutInspect saturated ramps and hidden-pattern fields to understand color coverage.Refresh RateMeasure the animation cadence your browser can sustain and watch for uneven pacing.GhostingFollow moving high-contrast blocks to spot trailing, smearing and inverse ghosting.BloomingBright shapes on black reveal halo spread from local-dimming zones.Burn-inCycle uniform colors and patterns to inspect OLED retention or uneven wear.Color BandingReveal stepped transitions in gradients that should appear smooth.ContrastCheck black-white separation and fine transitions at multiple line widths.HDRCompare highlight detail, deep blacks and vivid color in an HDR-ready pattern.Touch ScreenTrace a responsive grid to find dead zones, missed touches and inconsistent tracking.Screen TearingMove synchronized bars across the display to reveal tearing and frame pacing issues.Black LevelInspect near-black steps to check shadow detail, crush and panel uniformity.RGB ChannelCycle isolated red, green and blue fields to spot channel tint and stuck subpixels.sRGB ColorUse a compact sRGB reference palette to check clipping, tint and oversaturation.P3 GamutExplore vivid Display-P3 swatches and gradients on wide-gamut displays.BrightnessCompare luminance steps from near-black to white and check for clipping or unevenness.Gamma CalibrationTune mid-tone visibility with a neutral gamma reference pattern.FlickerShow controlled light and dark modulation to help reveal PWM or temporal dithering.Color DepthCompare stepped and dithered gradients to identify limited color depth or banding.Monitor ColorReview a complete color-card sequence for tint, clipping, uniformity and calibration drift.

Screen calculators and device testing guides

Calculate display dimensions or follow a focused checklist for your monitor, laptop, phone, TV, OLED or LCD screen.

Screen Size and PPI Calculator

Calculate physical width, height and pixel density from resolution and diagonal size.

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Screen Aspect Ratio Calculator

Simplify width and height into common ratios such as 16:9, 16:10 or 21:9.

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Screen Testing Guides by Device

Choose a monitor, laptop, phone, TV, OLED or LCD testing checklist.

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