Flask
A lightweight WSGI web application framework
71.3k GitHub stars
Flask vs FastAPI
Flask and FastAPI are both popular for APIs. Flask is minimal and flexible. FastAPI is newer and adds typing, validation, and API docs by default.
Quick Comparison
FastAPI
Modern, fast (high-performance) web framework for building APIs with Python 3.7+
95.9k GitHub stars
Ecosystem and Flexibility
Flask has a long plugin ecosystem and very few constraints.
FastAPI gives stronger conventions around request models and response schemas.
API Productivity
FastAPI usually reduces boilerplate for typed APIs.
Flask often requires additional libraries for validation and schema generation.
Verdict
Choose Flask for minimal custom stacks. Choose FastAPI when you want built-in validation, OpenAPI docs, and async-first design.
FAQ
Is Flask easier to learn than FastAPI?
Flask is often easier to start because it is minimal, but FastAPI can be faster for API projects due to built-in typing and schema tooling.
Can Flask handle production APIs?
Yes. Flask can power production APIs, but teams commonly add extra libraries for validation, serialization, and docs.