UD5 Toolkit
Webhook Tester & Inspector - Online View Incoming Payloads
Generate a temporary webhook URL (mock) and view the JSON payloads sent to it. Great for testing integrations locally.
API Tools - Development & Testing
37+ toolsPlatform Authenticator Demo - Online Fingerprint & Face ID
Test your device's built‑in biometric (Touch ID, Face ID, Windows Hello) using the Web Authentication API. Register and verify.
Shared Worker Demo - Online Cross‑Tab State
Set up a Shared Worker that shares state across multiple browser tabs. Counter and messaging demo. Advanced web.
WebAuthn Demo - Online Register & Authenticate
Create a passkey and authenticate using the Web Authentication API. Supports platform authenticators (TouchID, FaceID). No server.
Contact Picker API Demo - Online Select & Read Contacts
Pick a contact from the device’s address book (mobile). Read name, email, and phone. All permission‑based. Privacy safe.
Web Bluetooth Scanner - Online Explore Nearby Devices
Scan for nearby Bluetooth Low Energy devices using the browser. Read device names and signal strength. Experimental API.
Broadcast Channel API Demo - Online Cross‑Tab Communication
Open the same page in two tabs and send messages between them. See real‑time cross‑tab communication. Learn the API.
Permissions Query API Demo - Online Check All APIs
Query the permission state of camera, microphone, geolocation, and more. See the response and learn the API.
API Request Builder - Online Test REST Endpoints
Select HTTP method, set headers, and body. Send requests and see the full response. Lightweight Postman alternative.
Private State Token Demo - Online Anti‑Fraud Test
Issue and redeem Private State Tokens (formerly Trust Tokens). Understand how they help detect bots without cookies.
Web Share Level 2 Tester - Online Share Files
Test sharing multiple files (images, PDFs) using the Web Share API. Check if the browser supports file sharing. Demo page.
Cookie Store API Tester - Online Async Cookie Read/Write
Read, write, and delete cookies using the modern Cookie Store API. Monitor change events. No more document.cookie parsing.
URLPattern API Tester - Online Route Matcher & Playground
Write a pattern and test it against URLs instantly. See which groups match. Learn the modern alternative to regex for routing. Works entirely in the browser.
File System Access API Demo - Online Open & Save Files
Test the modern File System Access API. Open a file, modify it, and save back to disk. All sandboxed in browser.
File Handle API Demo - Online Persistent File Access
Use the File System Access API with file handles for persistent read/write. Learn incremental saving patterns.
Intersection Observer Sandbox - Online Visual Threshold
Adjust root, margin, and threshold. See a live log of intersection events as you scroll. Debug lazy loading.
Font Access API - Online Browse Local Fonts
Enumerate all fonts installed on your device and see a real‑time preview. Useful for design tools. Permission required.
Navigation API Playground - Online Single‑Page Router
Intercept and manage navigations without reloading. Test transition handling and URL updates. The future of client‑side routing.
GraphQL Request Tester - Online Simple Client
Enter a GraphQL endpoint, write a query, and see the response. Add headers and variables. Simple testing client.
Prioritized Task Scheduler Demo - Online scheduler.postTask()
Schedule tasks with user‑visible, user‑blocking, or background priority. See execution order and delays. Modern web perf.
Web Notification Tester - Online Permission & Display
Check notification permission, request it, and send a test notification. Verify icon, body, and tag. Debug web push.
Compression Streams API Demo - Online Gzip/Deflate Raw
Compress and decompress text using the browser's native Compression Streams API. See the binary output size.
FedCM Demo - Online Federated Credential Management
Experiment with the Federated Credential Management API. Simulate a sign‑in flow without third‑party cookies. Privacy‑first.
Web OTP API Demo - Online Auto‑Read SMS Codes
Demonstrate how the Web OTP API automatically reads one‑time codes from SMS (mobile). Simulation with a fake SMS input.
Screen Orientation API Tester - Online Lock & Check
Check current screen orientation and test the lock API. Useful for mobile web apps. Demo with code.
Web Locks API Demo - Online Resource Coordination
Acquire and release locks across tabs. Prevent race conditions in IndexedDB or localStorage. Visual queue and lock state.
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.
Idle Detection API Demo - Online User Activity Monitor
Request permission and detect when the user is idle (away from keyboard). See screen lock state. For native‑like apps.
Vibration API Demo - Online Test Haptic Feedback
Trigger different vibration patterns on mobile devices. Test if your phone supports haptic feedback. Simple demo.
GraphQL Query Builder - Online Visual Construct Request
Build a GraphQL query by selecting fields and nesting visually. Copy the built query string. For learning and fast prototyping.
cURL to Postman Collection - Online Simple Converter
Paste a cURL command and convert it into a minimal Postman collection JSON. Import and run. Local only.
Fullscreen API Tester - Online Request & Exit Demo
Test the Fullscreen API: request fullscreen on a colored div, detect changes, and copy the JavaScript boilerplate.
Pointer Events Playground - Online Mouse, Touch & Pen
Unified input demo: see pressure, tilt, and type from any pointer. Compare pointerType values. Essential for drawing apps.
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.
Swagger/OpenAPI YAML Previewer - Online Render & Test
Paste your Swagger/OpenAPI YAML and see a rendered API documentation preview with expandable endpoints. All local rendering.
GraphQL Playground - Online Query & Schema Explorer
Execute GraphQL queries against any endpoint with variables and headers. Explore schema via introspection. All requests made directly from your browser.
Clipboard API Tester - Online Read & Write Sandbox
Experiment with the Async Clipboard API: read/write text and images from the clipboard. Verify permissions and see demo code.