Flutter

Flutter is Google's open-source UI toolkit for building natively compiled, multi-platform applications from a single codebase, first released in 2018. Flutter uses the Dart programming language and its own rendering engine (Skia, now Impeller) to draw every pixel directly — unlike React Native which bridges to native components. This approach delivers pixel-perfect consistency across iOS, Android, web, Windows, macOS, and Linux from one codebase. Flutter's widget system is declarative and composable: every UI element is a widget (including padding, layout, and animations), enabling extremely customizable interfaces. Hot reload allows seeing UI changes in milliseconds during development. Flutter's growth has been rapid — it consistently ranks as one of the top cross-platform mobile frameworks in developer surveys (Stack Overflow, State of JS). Google uses Flutter for Google Pay, Google Classroom, and Stadia; Alibaba, BMW, eBay, and Nubank are notable enterprise users. The pub.dev package ecosystem has 35,000+ packages. Flutter's main strengths over React Native: better performance (no JavaScript bridge), more consistent cross-platform rendering, and faster animation frame rates (60/120fps). Weaknesses: larger app binary sizes, smaller ecosystem than React Native, and Dart's relatively small community versus JavaScript. Flutter is the best choice for teams wanting true pixel-perfect cross-platform apps without platform-specific UIs.