Web Feature Check vs Edsger

Discover What the Browser Really SupportsDiscover What the Browser Really Supports Web Feature Check helps developers, testers, and tech-savvy users instantly check which web technologies are supported in the current environment - whether it’s a mobile browser, embedded WebView, or custom in-app browser. Whether you're debugging quirks in mobile Safari or ensuring your web app works in limited environments, this tool gives you instant clarity. Key Features Check Runtime Web Features Detect supported JavaScript APIs, HTML5 elements, CSS features, media codecs, and more - all from the environment itself. Test Browser & WebView Capabilities Identify the exact feature set exposed by any browser, including embedded views and in-app browsers. Designed for Mobile Testing Quickly test on real devices - no desktop emulators, no guesswork. Test Categories and Coverage 1. HTML5 & Media Tests core media-related capabilities: - canvas, video, audio, picture, srcset - WebGL / WebGL2 - Picture-in-Picture 2. Audio & Media Processing Covers modern media and audio APIs: - Web Audio, MediaRecorder, ImageCapture - Web Speech API, Media Capabilities, Web MIDI 3. UX & Notifications Checks interaction and user feedback features: - Notifications, Fullscreen, Page Visibility - Web Share, Badging, Wake Lock, Vibration 4. JavaScript APIs Includes advanced JS platform features: - Service Workers, WebAssembly, Fetch, Streams - Clipboard, Crypto, ES6 Modules, Encoding API 5. Performance & Monitoring Observability & reactivity tools: - Intersection / Resize / Mutation / Performance Observers - Reporting API 6. Navigation & Communication Tests communication between contexts: - History & URL APIs - Beacon, BroadcastChannel, Server-sent Events - WebSockets, MessageChannel, XMLHttpRequest 7. Storage & Files Detects client-side data persistence options: - localStorage, sessionStorage, IndexedDB - File System Access, Cache Storage, File API - StorageManager & usage estimates 8. Input & Interaction Covers input modalities and interactivity: - Touch, Pointer, Drag-and-Drop - Gamepad, Pointer Lock, Viewport API - Selection API 9. Connectivity & Device Access Tests direct hardware or network integration: - WebRTC, Web Bluetooth, USB, Serial - Geolocation, DeviceMotion, Orientation, Battery, Network Info 10. Animation & Graphics Graphics rendering and animation pipelines: - Web Animations, WebGPU, WebCodecs 11. CSS & Layout Modern layout and visual CSS features: - CSS Grid, Flexbox, Container Queries, Subgrid - Backdrop-filter, View Transitions, Font Loading, Typed OM 12. Commerce & Payment E-commerce and data collection: - Payment Request API, Contact Picker 13. Security & Permissions Access and auth-related technologies: - Permissions, WebAuthn, Credential Mgmt, Trusted Types 14. Experimental APIs Emerging technologies still in draft or behind flags: - WebXR, Web NFC, Web Locks, WebTransport - Background Sync, Push API, Idle Detection, Compression Streams Scoring & Reporting - The app gives you a feature support score (e.g. 82/120) - Each category shows how many tests passed - Color-coded badges help you quickly interpret support levels (fully supported vs. unsupported) - Optionally, users can explore each feature’s MDN documentation directly from the interface

Edsger is a coding workspace for iPhone and iPad. Write C, Python, JavaScript or Lua, press Run, and your program runs right on your device. No account, no ads, and no network needed to write or run code. Ask Edsger, the built-in AI tutor, to explain code, fix an error or walk through a math or science problem. The free tutor and coding agent run entirely on your device, so your code and questions stay private. FOUR LANGUAGES, ON DEVICE • C with PicoC, a small interpreter • Python 3.14 with the standard library • JavaScript with JavaScriptCore • Lua 5.5 Each language has its own projects, syntax highlighting, console input and Stop. AI THAT HELPS YOU LEARN • Chat: ask questions, attach documents, and get step-by-step math • Agent IDE: describe a change and the agent reads, edits and runs files in your project, with restore points • On-device models are free and work offline EDSGER PRO (OPTIONAL SUBSCRIPTION) • Dijkstra Super Fast 1.0, a faster cloud model for Chat and the Agent IDE, with a monthly AI allowance • Photos in Chat with Dijkstra • Bring your own OpenAI or Claude API key • Push projects to your GitHub account • A custom Chat note and extra colors Pro Plus includes three times the Pro allowance. Cloud AI only runs after you allow sharing, and you can turn it off anytime. HONEST LIMITS C runs in PicoC, not GCC or Clang, so some standard library features are missing. Python, JavaScript and Lua run without package installs, network access or GUIs. AI can make mistakes; review its code and don't rely on it for medical, legal or financial advice. Subscriptions renew monthly unless canceled at least 24 hours before the period ends. Manage them in your Apple Account settings. Terms: https://garrettmichae1.github.io/lilc/terms.html Privacy: https://garrettmichae1.github.io/lilc/privacy.html