FastAPI
A modern, fast web framework for building APIs with Python
A high performance, easy to learn, fast to code, and ready for production framework
Reviews for FastAPI
Hear what real users highlight about this tool.
Makers consistently praise FastAPI for cutting boilerplate and speeding delivery. The makers of Polar highlight automatic OpenAPI generation that streamlines SDK creation and keeps focus on business logic. The makers of Writesonic call it a very capable backend choice, while the makers of Reflex report smooth async state updates, file uploads, and clean API routing. Broader feedback applauds strong performance, clear docs, and easy validation/DI, with several teams switching from Flask for faster iteration and more maintainable codebases.
This AI-generated snapshot distills top reviewer sentiments.
Trace-AI’s core services are built using FastAPI for its async-first design and blazing performance. It allows us to deliver lightweight, responsive API endpoints for dependency scoring and compliance automation.
Nice backend, good performance, simple syntax, and very very good documentation (especially compared to Flask)!
I don't really think about the fastapi very much in the project, which I think is the whole point. It's easy to generate a typed API client, and easy to keep the project organized. It sufficiently just works that I will continue to reach for it.
FastAPI makes backend development incredibly fast and enjoyable. Its async support and auto-generated documentation make it far smoother than traditional frameworks like Flask or Django.
Thanks to FastAPI for enabling blazing-fast API development with automatic documentation and type safety. It's become our go-to framework for building production AI endpoints that are both developer-friendly and performant at scale.
FastAPI makes sending data from front end to server and back to front end a whole lot easier. With FAST API, loading my machine learning model and making predictions are extremely easy. And with its JSONResponse method, I can easily send data in the desired format back to my app's backend which will then be sent over to the front end after processing. I considered Flask, but FastAPI is generally better for tasks like these in my opinion.
FastAPI runs our API gateway and WebSocket chat with async performance and type-safe validation.
FastAPI makes backend development smooth and lightning-fast. Its async design and simple syntax were perfect for powering FreeToolyz’s API layer.
For the API layer, FastAPI was a clear winner. Its asynchronous performance is incredible for handling concurrent AI model requests, and the automatic OpenAPI documentation saved me countless hours. It provides the speed and simplicity of modern Python.
FastAPI gave us a lightweight alternative for API endpoints during development — incredibly fast and intuitive.
Enables lightning-fast API responses for our RAG system, making T24 code generation and documentation search feel instantaneous and smooth.
FastAPI powers our backend with blazing speed, intuitive syntax, and async support—ideal for modern Python apps.
Our backend is built on FastAPI, and it’s been a dream to work with. It’s fast, clean, and developer-friendly. It gave us the speed to iterate quickly while still being production-ready.
Tip: 👉 Combine FastAPI with SQLAlchemy + Pydantic for a full production-ready stack.
Alternatives considered: Django — too heavy and opinionated for our lightweight MVP. Flask — flexible but lacked the built-in speed and async support we needed.