Best Dart Open Source Repositories

Dart is a statically typed language developed by Google, best known as the language behind Flutter, the cross-platform UI toolkit for building mobile, web, and desktop applications from a single codebase. Dart compiles ahead-of-time to native machine code for production mobile and desktop builds, which gives Flutter apps fast startup times and smooth performance, while also supporting just-in-time compilation during development for Flutter's hot reload feature, letting developers see code changes reflected in a running app within roughly a second.

Outside of Flutter, Dart also compiles to JavaScript for web deployment and can be used to write standalone command-line tools and backend services, though its adoption in those contexts is much smaller than its use inside the Flutter ecosystem. The language supports null safety, sound typing, and modern async programming patterns through Futures and Streams, features aimed at making large mobile app codebases easier to maintain as they grow.

Because Dart's popularity is closely tied to Flutter, most open-source projects using it are Flutter-based mobile or desktop applications. Repos on this page written in Dart include Flutter itself, Immich, a self-hosted photo and video backup solution with a Flutter mobile client, AppFlowy, an open-source alternative to Notion built with Flutter for its cross-platform interface, and Ente, an end-to-end encrypted photo storage app that also uses Flutter and Dart for its client applications.