Mac storage basics · Programming languages and toolchains
How do I free space used by Flutter and Dart projects?
Short answer: Run flutter clean in each project to delete its build folder, and dart pub cache clean to empty the shared package cache. Both rebuild when needed.
Each Flutter project builds into its own build folder, which can be large. Run flutter clean inside a project to delete it; it's rebuilt next time you run the app.
Packages are shared in the pub cache. dart pub cache clean empties it (packages download again when needed). If you also build for Android or iOS, those toolchains have their own caches — see Android Studio and emulators and Xcode.