Detect available browser features
- ES6
- CSS.registerProperty
- Promise.allSettled
- Web Components v0
- Web Components v1
- IntersectionObserver
- fetch()
- Service worker (HTTPS only, may fail)
- Local Storage (may get declined)
- requestAnimationFrame
- requestIdleCallback
- visibilityState (might not be accurate)
- CSS Font Loading API
- Network Information API (might not be accurate)
- WebXR device API
- WebVR 1.1 API
- WebGL
- WebSocket