Web Feature Check 4+

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