How does the screen refresh rate (Hz) detection work?

The tool uses requestAnimationFrame() timing to measure the actual render frequency of your display. It counts consecutive frames over a 1-second window and reports the real refresh rate (60Hz, 120Hz, 144Hz, 240Hz) your browser is delivering.

Can I detect dead pixels on a laptop screen using this tool?

Yes! Enter fullscreen mode and cycle through solid color backgrounds (red, green, blue, white, black). Carefully scan the entire display surface for any dots that remain a different color from the background — those are dead or stuck pixels.

What is contrast gradient banding and how do I test for it?

Gradient banding appears as visible steps or stripes in smooth color transitions, indicating your display has limited color depth (6-bit vs 8-bit panels). Our gradient test renders smooth transitions from black to white and across color channels to expose banding artifacts.

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Hardware Testers•Refresh Rate (Hz)

Screen Display & Dead Pixel Checker

Check screen refresh rate (Hz), detect dead pixels with fullscreen color cycles, and test contrast gradient banding.

Instant browser processing Private & Auto-Purged

Hardware TestersRefresh Rate (Hz)60 Hz • 1920×1080

Screen Display & Dead Pixel Checker

Check screen refresh rate (Hz), detect dead pixels with fullscreen color cycles, and test contrast gradient banding.

🔒 100% In-Browser Hardware Diagnostic

Zero camera frames, microphone audio, keystrokes, or gamepad telemetry are transmitted to any server. Diagnostics run entirely inside your browser's local sandbox.

Refresh Rate

60.0Hz

60 Hz Standard Desktop

Frame Delivery

Optimal

16.67ms

Jitter: ±0.15ms

Display Geometry

Optimal

1920×1080(16:9)

Scale: 1x | 24-bit

1% Low Stability

Optimal

59FPS

0 Dropped Frames

Zero-Distraction Fullscreen Diagnostic

Find Stuck & Dead Pixels in Pure Fullscreen

Launches an edge-to-edge solid color field with zero UI elements to detect defective subpixels, backlight bleed, and OLED burn-in with maximum visual contrast.

Test Color Sequence & Fault Targets

Click any color below to preview its specific diagnostic purpose:

Dead Pixels (Black Dot on White)

A dead pixel is completely unpowered and will show as a tiny black square on pure white and bright primary backgrounds.

Stuck Pixels (Bright Dot on Black)

A stuck pixel has one or more subpixels stuck in the ON state. It shows up as a bright red, green, or blue dot against pure black.

IPS Glow & Backlight Bleed

Best observed on 50% gray and black in a dim room. Uneven bright patches at screen corners indicate backlight bleed.

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How to Convert with Screen Display & Dead Pixel Checker

Follow these 3 simple steps to complete your conversion in seconds.

Step 1 of 3

Grant Browser Permissions

Click "Start Test" and allow browser access to your camera, microphone, or peripherals when prompted. All data stays 100% local in your browser.

💡 Tip: No data is recorded, uploaded, or stored. Zero server contact.

Step 2 of 3

Run Interactive Diagnostics

The tool runs real-time diagnostics on your hardware, measuring resolution, frame rate, volume levels, latency, drift, and other device-specific metrics.

Step 3 of 3

Review Results & Share Report

View your live diagnostic scorecard with pass/fail indicators. Copy results to share with IT support or embed this test on your own website.

Screen Display & Dead Pixel Checker Browser Diagnostic API & Technical Specification

Formula representation used for accurate calculations:

MediaDevices API: navigator.mediaDevices.getUserMedia({ video: { width, height, frameRate }, audio: true }) Refresh Rate: requestAnimationFrame() frame count per 1-second window Gamepad API: navigator.getGamepads() polling axis/button state at 16.67ms intervals

Calculation Example: Webcam: 1920×1080 @ 30fps via getUserMedia constraint negotiation. Screen: 144Hz detected via 144 RAF callbacks per 1000ms window.

Hardware Diagnostic Test Capabilities & Browser API Reference

Quick reference lookup table for standard unit calculations.

All diagnostics execute 100% client-side in your browser using standard Web Platform APIs. Zero data is uploaded or recorded.
Diagnostic Tool	Browser API Used	Key Metrics Measured
Webcam Tester	MediaDevices.getUserMedia (video)	Resolution (720p/1080p/4K), FPS, device label, codec support
Microphone Tester	MediaDevices.getUserMedia (audio)	Volume level (dB), noise floor, echo loopback, sample rate
Speaker Tester	Web Audio API (AudioContext, OscillatorNode)	L/R stereo channels, frequency sweep (20Hz–20kHz), bass response
Screen Display Tester	requestAnimationFrame, Fullscreen API	Refresh rate (Hz), dead/stuck pixels, contrast gradient banding
Keyboard Tester	KeyboardEvent (keydown/keyup)	Key map verification, N-Key Rollover, ghosting, switch chatter
Mouse Tester	MouseEvent, WheelEvent	Click buttons, scroll delta, polling rate, double-click fault
Gamepad Tester	Gamepad API (navigator.getGamepads)	Stick drift %, trigger pressure, button map, rumble motors
Call Readiness	MediaDevices + RTCPeerConnection	Camera/mic/speaker pass/fail, WebRTC latency, readiness score

Frequently Asked Questions

Common questions and answers about Screen Display & Dead Pixel Checker.

A dead pixel is permanently off (black dot on white background), while a stuck pixel has subpixels stuck on (bright red, green, or blue dot on black background).