FastAPI is a modern, high-performance web framework for building APIs with Python, designed to deliver speed, simplicity, and reliability. Built on top of Starlette for the web layer and Pydantic for data validation, FastAPI leverages Python’s type hints to automatically generate request validation, serialization, and interactive API documentation using OpenAPI and Swagger UI. This combination provides developers with a seamless experience where code, validation, and documentation remain perfectly in sync.
One of FastAPI’s defining strengths is its speed—comparable to Node.js and Go, thanks to its asynchronous support built on Python’s async and await syntax. This makes it ideal for handling large-scale, concurrent applications such as microservices, IoT backends, and machine learning model deployment.
Beyond performance, FastAPI emphasizes developer productivity and security. It includes built-in support for OAuth2, JWT authentication, and dependency injection, reducing boilerplate while maintaining flexibility. Because of its intuitive design, clear error handling, and automatic API generation, FastAPI has become a top choice for teams building modern, scalable APIs that need to move fast without sacrificing code quality or maintainability.