Flask and Django are mature, extensible web frameworks that fundamentally provide similar functionality in handling requests and maintaining documents but differ in scope.
Most of the differences between the two frameworks stem from different approaches, the rest from excellent basic design decisions. Here are a few key differences that might influence your decision:
Request object – Flask uses local streams, and Django passes the request where it needs to be.
Forms – Django is available with built-in forms that integrate with the ORM and site admin area. Flask doesn’t support forms by default, but you can use WTForms to fill that gap.
Databases – Django is available with a built-in ORM and migration system that can manage databases. Flask doesn’t do that, but tools like SQLAlchemy provide similar functionality (or even more).
Authentication and User Privileges – Django provides an authentication application that provides a default implementation for user control and privileges. Flask provides secure cookies as a tool for your own implementation.
Admin Panel – Django includes a fully integrated admin interface for managing application data. Flask doesn’t have these features, but Flask-Admin is a very popular extension that can be used to create a similar admin tool.