What did you notice?

Choose the closest visible symptom. You can change the selection before opening a test.

Suggested next checkStart with the Dead Pixel Test

Compare the fixed point on white, red, green, blue, and grey fields.

Choose by symptom, category, or device

Screen Test and Screen Tester Toolkit

This screen test hub routes a visible symptom to the smallest useful browser tool, then groups the complete screen tester collection by panel area, color and tone, motion, advanced behavior, and device workflow. Every link opens a distinct interactive check or task sequence.

Complete toolkit

Screen testing organized by the question you need to answer

Open one focused tool first. Add another category only when the observation calls for a different reference.

Pixel & Panel

Locate a point or compare a panel area

Start here for a fixed dot, bright edge, broad tint, or a solid black or white field.

Dead PixelSolid fields for a systematic visual scan Stuck PixelIndividual and mixed RGB channel comparison Backlight BleedLCD edge light versus viewing-angle glow UniformityGrey, white, RGB, grid, and panel zones Black ScreenBlack and near-black fullscreen fields White ScreenBright neutral fields and zone references

Color & Tone

Inspect channels, steps, and visible separation

Use these patterns for visual tone behavior, not instrument-grade color or luminance measurement.

Screen ColorRGB, CMY, custom, split, and ramp fields GrayscaleGrey steps, ramp, uniform field, and endpoints RGBPrimary fields, ramps, steps, and additive mixes BandingSmooth and deliberately stepped gradients GammaVisual fusion references for several target responses ContrastShadow, highlight, checker, and shape separation Black LevelAdjustable near-black bars, steps, and fields

Motion

Name cadence, trails, and discontinuities

Browser animation provides a moving reference while keeping timing and compositing limitations visible.

Refresh RateBounded requestAnimationFrame cadence estimate GhostingMoving edge polarities, speeds, and backgrounds Screen TearingMoving bars, checkerboard, grid, and marker MotionThree synchronized lanes and focused next steps

OLED & Advanced

Check persistent shapes, dark tones, and dimming behavior

Confirm the display technology before applying OLED, LCD, or local-dimming terminology.

Burn-InCautious retention and differential-aging fields Near-BlackLow-grey fields, ramp, and patch grid BloomingIsolated static and moving targets on black Local DimmingMultiple targets, sweeps, and stress patterns ResolutionViewport, Screen API, DPR, and fullscreen context

Device Workflows

Run the tools in an order suited to the display

These are not device-name copies. Each workflow changes the order, preparation, panel branch, observation distance, and limitations for the hardware and browser context.

MonitorNew and used desktop-display sequences LaptopScaling, DPR, power, lid angle, and panel type PhoneTouch-first fields, rotation, OLED care, and pointer coverage TVSignal path, viewing distance, OLED, LCD, Mini LED, and motion OLEDRetention, near-black, grey uniformity, tint, and black LCDBacklight, glow, clouding, tone, and liquid-crystal motion

A symptom-to-interpretation path

Start narrow, compare, then document

A single dark point calls for solid fields, while a fixed colored point benefits from an RGB channel comparison. Bright LCD corners need a dark field plus a viewing-angle change. A striped gradient belongs in the banding tool; a moving trail belongs in ghosting; an old interface shape on an OLED belongs in the retention workflow; a halo around a bright object belongs in blooming.

After locating the relevant screen test, repeat the observation without changing several settings at once. Record the pattern, panel coordinate or area, brightness, picture mode, viewing position, room light, and whether the appearance changes with color, angle, or motion. That record is more useful than a synthetic health score the browser cannot justify.

Know when a visual check has reached its limit

A visual screen tester can help you describe what you see. Physical measurement requires an appropriate meter, controlled signal path, and documented method. Hardware identification, repair, warranty thresholds, and replacement decisions belong with reliable device documentation and the relevant retailer, manufacturer, or qualified service provider.

For pixel terminology and a repeatable first scan, continue to thedead-versus-stuck explanation or the dead pixel testing guide.