What They Have in Common
React Native and Flutter both let a single codebase target iOS and Android, both have mature ecosystems, and both are used in large, high-traffic production apps — neither is the 'toy' option at this point.
Where React Native Tends to Win
Teams already comfortable with JavaScript/TypeScript and React's component model pick up React Native fast, and it integrates naturally with an existing React web codebase or team. It leans on native platform components more directly, which can help UI feel platform-native by default.
Where Flutter Tends to Win
Flutter renders its own UI layer (via the Skia/Impeller engine) rather than using native components, which gives more precise, consistent control over complex custom UI and animation across both platforms — at the cost of the app needing to feel intentionally designed rather than relying on OS defaults. Dart is also a smaller hiring pool than JavaScript, which matters for team continuity.