Flutter is Google's open-source SDK for building beautiful, fast user experiences across mobile, web, and desktop platforms from a single codebase written in Dart. The framework enables developers to create native applications for iOS, Android, Windows, macOS, Linux, and web, as well as to embed Flutter as a UI toolkit in other platforms.
The framework's architecture prioritizes pixel-perfect control and creative flexibility. Flutter includes comprehensive widget libraries for both Material Design and Cupertino (iOS) design systems, allowing developers to deliver platform-specific visual experiences. The layered architecture gives developers control over every pixel on screen, with powerful compositing capabilities for overlaying and animating graphics, video, text, and controls without limitation. This design philosophy enables designers to realize their full creative vision rather than being constrained by framework limitations.
Performance is a core design principle of Flutter. The framework leverages hardware-accelerated 2D graphics libraries including Skia, which powers Chrome and Android, and Impeller for optimized rendering. Dart code compiles to native machine code for mobile platforms, JavaScript and WebAssembly for web, and Intel x64 and ARM architectures for desktop, enabling glitch-free and jank-free graphics at native device speeds.
Developer productivity is enhanced through stateful hot reload, which allows developers to make code changes and see results instantly without restarting the application or losing its state. The framework supports integration with existing code through Foreign Function Interface (FFI) on Android, iOS, macOS, and Windows, as well as platform-specific APIs via platform channels. Flutter works with any development tool and includes editor plugins for Visual Studio Code and IntelliJ/Android Studio.
Flutter provides access to tens of thousands of packages to accelerate development across target platforms. The framework is free and open source, welcoming community contributions through a documented contributor guide. The SDK requires agreement to Google's Terms of Service, as the Flutter tool occasionally downloads resources from Google servers, including the Dart SDK when installed from GitHub.
