Web Feature Check vs Walnut

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

The ultimate developer tool for testing WKWebView and SFSafariViewController configurations in real-time. KEY FEATURES WKWebView Testing • Real-time configuration testing with 20+ options • Built-in DevTools: Console, Network, Storage, Performance, Sources, Accessibility • JavaScript injection and snippet execution • Custom User-Agent emulation • Viewport and device emulation SFSafariViewController Testing • Native Safari experience with content blockers • Reader mode and responsive size control • Customizable bar colors and dismiss button styles Developer Tools • Console: Capture console.log with %c CSS styling support • Network: Monitor fetch/XHR requests with timing data • Storage: View/edit localStorage, sessionStorage, cookies • Performance: Web Vitals (LCP, FID, CLS) and Navigation Timing • Sources: DOM tree inspection, stylesheets, scripts • Accessibility: axe-core based accessibility auditing Additional Features • Bookmark management for quick URL access • Responsive viewport resizing (iPhone, iPad, Desktop presets) • Screenshot capture • API capability detection • Dark mode support Perfect for iOS developers who need to test web content rendering, debug JavaScript, analyze network requests, and ensure accessibility compliance.