UD5 Toolkit
Eye Dominance Test - Online Find Your Dominant Eye
Simple interactive eye dominance test: hold up a virtual dot and see which eye stays aligned. Educational.
Tag: Network Connectivity Test
70+ toolsAudio/Video Sync Tester - Online Lip Sync Check
Load a video and visually check if audio aligns with lips. Use frameâbyâframe stepping. Debug playback issues.
Fuzzy Data Generator - Online Create Random Records
Generate random but realisticâlooking data arrays (users, products, orders) with typos and missing fields. For test robustness.
Astigmatism SelfâCheck Chart â Online Dial & Lines
Display an astigmatism dial and instructions for self-assessment. Educational, not a medical diagnosis.
Network Throttle Simulator - Online Slow 3G & Offline Test
Test how your page loads under slow, 3G, or offline conditions by intercepting fetch and applying delays. No DevTools needed.
Fullscreen API Tester - Online Request & Exit Demo
Test the Fullscreen API: request fullscreen on a colored div, detect changes, and copy the JavaScript boilerplate.
Speaker Polarity Test â Online Click & Listen
Generate a pop signal to determine if speakers are wired in phase. Quick stereo test.
Browser Color Gamut Test - Online P3 or sRGB?
Check if your browser and display support the wider DCIâP3 color space. See the difference with a simple test pattern.
Iframe Sandbox Configurator - Online Test Permissions
Build an iframe with different sandbox flags and see live which features are blocked. For secure embedding.
Fake ID Number Generator - Online Test SSN/SIN Lookalike
Generate random, formatted ID numbers that match pattern rules for various countries. For testing input validation. No real data.
Media Device Tester - Online Check Camera, Mic & Speaker
Quickly test if your webcam, microphone, and speakers work correctly. See live video and audio meter. No data sent.
Screen Orientation API Tester - Online Lock & Check
Check current screen orientation and test the lock API. Useful for mobile web apps. Demo with code.
Random User Activity Simulator - Online Test Idle Logic
Simulate random mouse moves, clicks, or keystrokes to test idleâtimeout logic. Stops when you move the mouse. Dev test.
Microphone Sensitivity Tester - Online Input Level Meter
See a live VU meter of your microphone's input level. Test if your mic is working and adjust gain. Privacyâfriendly.
Speaker Test Tones - Online Left/Right Channel & Sweep
Play leftâonly, rightâonly, and frequency sweeps to test your speakers or headphones. Quick audio check.
Spelling Test Practice - Online Audio Dictation & Typing
Hear a word spoken by browser TTS and type the spelling. Choose difficulty or paste your own list. Great for kids. Local only.
Web Share API Tester - Online Demo & Code
Test the Web Share API by sharing text, links, and files directly from the browser. Check compatibility and see example code.
Test Credit Card Validator - Online Luhn Check & Issuer
Paste a test card number to verify Luhn algorithm, identify issuer (Visa, MC), and check length. No real data.
AcceptâLanguage Header Visualizer - Online Locale Match
Paste your AcceptâLanguage header and see which languages your site should serve based on quality values. Internationalization helper.
Geolocation API Simulator - Online Test Coordinates
Override your browser's geolocation to any coordinates and test how your app responds. For development and privacy testing.
Palindrome Tester - Online Phrase Checker
Enter any phrase and instantly see if it's a palindrome, ignoring spaces and punctuation. Fun for word nerds.
HTTP Request Composer - Online Build & Send Requests
Pick a method, URL, headers, and body, then send an HTTP request directly from your browser. Debug APIs easily.
Screen Wake Lock Tester - Online Keep Screen On
Toggle a screen wake lock to prevent the device from dimming or sleeping. See the lock state and learn the API.
Geolocation Override Tester - Online Simulate Any Location
Override your browser's geolocation to any coordinates and test how your app responds. For development and privacy testing.
Speech Utterance Tester - Online Play Word by Word
Hear text spoken word by word with boundary events. See the exact index and character. Advanced TTS dev tool.
PWA Install Prompt Tester - Online Simulate Install
Check if your page triggers the beforeinstallprompt event. Simulate the install flow. Debug PWA installability.
Reaction Time Test - Online Click & Sound
Measure your visual and auditory reaction speed. Average and best times shown. No data collected. Pure Javascript timing.
Visual Stress Pattern Checker â Online See Effect
Display striped patterns that can cause visual distortion. Learn about visual stress. Switch colors.
Random MAC Address Generator - Online Hardware Test IDs
Generate valid, random unicast MAC addresses for testing or spoofing. Select OUI prefix if desired. Local only.
MultiâDevice Tester - Online See Website on 3 Sizes
Enter a URL and view it in three iframes: mobile, tablet, and desktop sideâbyâside. Quick responsive check.
Online Ping Test - Measure Latency to Servers
Send HEAD requests to popular websites and measure the roundâtrip time. Quick network health check. Clientâside.
API Request Builder - Online Test REST Endpoints
Select HTTP method, set headers, and body. Send requests and see the full response. Lightweight Postman alternative.
Clinical Color Blindness Tester - Online Ishihara Plate Style
View a series of digital Ishiharaâstyle plates. Not a diagnostic tool, just educational. Read numbers.
Periodic Background Sync Tester - Online Register & Test
Register a periodic background sync and see the status. Schedule content updates for your PWA. API demo.
Offline Capability Checker - Online Test PWA Readiness
Check if your site has a service worker registered and if it can load offline. Quick PWA readiness assessment.
Web Notification Tester - Online Permission & Display
Check notification permission, request it, and send a test notification. Verify icon, body, and tag. Debug web push.
Subwoofer Phase Tester â Online Audio Check
Play low-frequency tones to check subwoofer phase alignment with main speakers. Simple tool.
Unicode Normalization Tester - Online See NFC vs NFD
Paste two strings that look the same and see if they differ after normalization. Debug invisible encoding bugs.
PseudoâLocalization Generator - Online Test UI for i18n
Transform English text into pseudolocalized text with accents, expansion, and brackets. Test your UI's readiness for translation.
Push Notification Tester - Online Generate & Receive
Register a service worker, subscribe to push, and send a test notification using a VAPID key pair. Stepâbyâstep demo.
SSE (EventSource) Tester - Online Stream Listener
Connect to an SSE endpoint and display events in real time. Inspect event types and data. Handy for frontend devs.
prefersâreducedâmotion Tester - Online A11y Check
Simulate reduced motion preference and test your animations. Copy the media query snippet. Keep your users safe.
Finger Reaction Time Test â Online Tap When Color Changes
Wait for the box to turn green, then tap as fast as possible. Measure milliseconds. Compete with friends.
Regex Lookaround Tester - Online Experiment with Lookahead
Practice positive/negative lookahead and lookbehind. See matches highlighted live. Master advanced regex.
WebTransport Echo Client - Online QUIC Test
Connect to a WebTransport server and exchange data over QUIC. See latency and throughput. Perfect for exploring lowâlatency realâtime APIs.
XâFrameâOptions Tester - Online Clickjacking Defense
Check if a URL can be embedded in an iframe. Test your siteâs defense against clickjacking. Browserâbased.
WebSocket Test Client - Online Connect & Send Messages
Connect to a WebSocket endpoint, send messages, and view the stream of received data. Perfect for debugging realâtime apps.
Connection Speed Estimator - Online Download Test
Quickly estimate your internet connection speed by downloading a small test file. See class and recommendations.
Web Share Target Tester - Online Receive Shared Content
Simulate a PWA receiving shared text, links, and images. Test the Web Share Target API without a server.
CORS Proxy Emulator - Online Test CrossâOrigin Requests
Bypass CORS for testing by routing requests through a local service worker proxy. Debug APIs without server changes. Experimental.
Playwright Test Skeleton - Online Script Boilerplate
Create a basic Playwright script with browser launch, page navigation, and screenshot. Start E2E testing instantly.
Random English Name Generator - Online First & Last
Generate a random first and last name typical for US, UK, or Australia. With optional middle initial. Useful for test data.
Snellen Eye Chart â Online Visual Acuity Test Simulation
Display a Snellen chart on screen and mark distance for a fun self-test. Not a replacement for professional exam.
Notification Permission Checker - Online Manage & Test
See your current notification permission status. Request or reset it. Test browser notification behavior.
3D Printer Bed Leveling Test Generator â Online STL Preview
Create a simple 3D bed-leveling test pattern (circles/squares) as a vector, preview, download SVG for extrusion.
HandâEye Coordination Test â Online Click Targets Game
Click moving targets as fast as possible. Score time and accuracy. Fun benchmark.
Speech Dispatcher Tester - Online Explore All Voices
List all available TTS voices on your system. Test each with any text. Adjust rate and pitch. Find the best voice.
Candle Wick Testing Log â Online Record & Compare Burn Results
Log pool depth, flame height, and soot for each wick series. Quickly identify the best wick for your wax and vessel.
React Testing Library Skeleton - Online Test Boilerplate
Enter a component name and generate a complete RTL test file with render, screen, and common assertions. Fast testing setup.
forcedâcolors Mode Tester - Online Windows High Contrast
Simulate forcedâcolors mode and see how your site looks. Adjust CSS system colors. Make your design accessible.