Browser APIs

Beyond the DOM, browsers expose dozens of APIs: fetch for network requests, Web Storage and IndexedDB for keeping data, Canvas and WebGL for drawing, Web Audio, WebRTC for calls, Geolocation, Clipboard, Notifications and Push, Web Share, and service workers for offline support. Together they let a web app do much of what once needed a native app.

Powerful features ask the user first (camera, microphone, location, notifications) and work only on HTTPS pages. Support varies between browsers and versions, so MDN and caniuse.com are the usual places to check before relying on one, along with a fallback for browsers that lack it.