When BLoC is too much
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Flutter's BLoC (Business Logic Component) library has earned its reputation for discipline and testability, but it is not a default choice for every code-base. Below are objections that come up again and again when teams decide to move away from BLoC.
Heavy boilerplate slows momentum
A single feature typically spawns three new files: events, states, bloc and the widget glue. Even BLoC
supporters publish "boilerplate-reduction" packages such as warped_bloc whose entire raison-d'être is to hide
repeated code.
Flutter's own MVVM sample contrasts sharply: one ChangeNotifier
class and a couple of
notifyListeners()
calls.
Steep learning curve for newcomers
Stream
s, yield*
, BlocObserver
, transformEvents
and
Equatable
impose a conceptual tax that new hires must pay
before shipping UI. Medium tutorials routinely list "steeper learning curve" as the first disadvantage of BLoC
compared with Riverpod or MVVM.
Over-engineered for small & medium apps
When the UI and its state are tightly coupled-think toggles, animations, or short-lived wizards-BLoC's separation offers little benefit and a lot of ceremony. Writers who once championed BLoC now warn that it is "overkill for smaller projects with limited state-needs".
File-hopping hurts flow
... and brain. A change to one user flow can mean touching four or five scattered files. Even with IDE navigation, reviewers and refactorers spend non-trivial time rediscovering where a particular state or event lives-a problem Provider or Riverpod sidestep by co-locating logic and view code.
Async race conditions & event queues
Because events are queued and processed sequentially, long-running operations can starve UI feedback or emit stale states. Developers hit “state ping-pong” when two blocs dispatch to each other in a loop; community Q&A threads are filled with workarounds that move logic back into widgets.
Unnecessary rebuilds
Stream emissions bubble through BlocBuilder
s that may sit high in the widget tree, triggering
renders far below.
Critics note that nested, irrelevant rebuilds can appear unless you sprinkle extra BlocSelector
s or
split blocs
more finely.
Verbose cross-bloc communication
BLoC has no built-in composition mechanism. If Feature A needs data from Feature B you either:
- Chain listeners in the widget layer (mixing UI and domain logic).
- Create global singletons that undercut the strict boundary BLoC set out to provide.
Version churn & lock-in
flutter_bloc 8->9 removed default transition logs and changed BlocObserver
APIs. Major upgrades
often demand
code-mods across dozens of blocs. Swapping to a lighter solution later means rewriting every event/state pair.
Performance head-room rivals offer natively
Riverpod, GetX and even vanilla InheritedModel
give finer-grained listeners without the manual
splitting BLoC
requires, while also bundling dependency-injection or caching that BLoC lacks.
Flutter's modern docs steer elsewhere
Google's own architecture guide (2024) demonstrates MVVM with notifier-based models and explicitly calls out boilerplate as a trade-off rather than a best practice . When the framework authors do not recommend a pattern by default, that is a data-point worth weighing.
Conclusion
Choosing a state management strategy is about optimizing for today's pain, not tomorrow's trend. Flutter's widget tree already gives you a simple, reactive loop. Use BLoC only when the payoff in testability, predictability or team discipline clearly outweighs the undeniable costs in boilerplate, learning time and cognitive load.