Mobile Frameworks

Flutter175.8k★

Flutter builds natively compiled applications for mobile, web, and desktop from a single Dart codebase. You write in Dart, and Flutter renders everything with its own engine: no native UI components, no web views, just pixels painted directly to the screen. That means your app looks identical on every platform. BSD 3-Clause, Dart. The widget system is composable: everything is a widget, you nest them like LEGO bricks. Hot reload is fast, making UI iteration feel instant. The package ecosystem (pub.dev) has thousands of plugins for maps, payments, cameras, Bluetooth, and more. Completely free. No paid tier, no usage limits, no premium SDK features. Google uses it for their own apps (Google Pay, Stadia, Ads) and maintains it as a free tool. Solo: free, excellent for shipping to both app stores from one codebase. Small teams: free, huge time savings vs maintaining native iOS + Android separately. Medium: free, strong for teams without native mobile expertise. Large: free, but evaluate whether platform-specific UX matters enough to justify native development. The catch: Dart. Almost nobody learns Dart for anything other than Flutter. The talent pool is smaller than React Native's JavaScript ecosystem. Flutter's custom rendering means your app won't look or feel exactly like native iOS or Android; Material Design everywhere. Some packages are poorly maintained. And web support, while functional, produces large bundles that don't feel like a real web app.

React Native125.7k★

React Native builds actual native mobile apps with native UI components, not a website wrapped in a phone frame. React Native is the most battle-tested way to do it. Write your app in JavaScript/TypeScript using React components, and it renders native iOS and Android UI. One codebase, two platforms. This is Meta's own framework, used in Facebook, Instagram, and Messenger. That scale proves it works in production. The ecosystem is enormous: navigation libraries, UI kits, native module bridges, and thousands of community packages. The New Architecture (Fabric renderer, TurboModules) has made performance significantly better than the old bridge-based system. Completely free under MIT. No paid tier from Meta. Flutter is the main competitor: Dart instead of JavaScript, pixel-perfect rendering instead of native components. Expo simplifies React Native development significantly by handling the native toolchain for you. If you're starting fresh with React Native, start with Expo, not bare React Native. The catch: "learn once, write anywhere" still means platform-specific work. Complex animations, native APIs, and platform-specific UI patterns require writing native code (Swift/Kotlin) or finding a library that bridges it. Debugging can be painful; you're debugging across JavaScript, native, and the bridge layer. Build times are slow. And the upgrade path between versions has historically been rough, though it's improving.