fastapi vs tornado
Python API development and asynchronous networking compared
fastapi and tornado are Python projects for building web services. fastapi focuses on typed HTTP APIs with validation and generated OpenAPI documentation, while tornado combines web request handling with non-blocking networking for persistent connections.
fastapi: Build APIs with Python type hints
FastAPI is a Python web framework for building HTTP APIs from standard type annotations. It validates and converts request data and generates OpenAPI documentation, making it a fit for teams that want typed API development with interactive docs.
tornado: Build Python Web Apps and Async Network Services
Tornado is a Python web framework and asynchronous networking library built on Python's non-blocking I/O model. It is designed for web apps with long-lived connections, including long polling and WebSockets.
| fastapi | tornado | |
|---|---|---|
| Language | Python | Python |
| License | MIT | Apache-2.0 |
| Stars | 103k | 22.2k |
| Forks | 10k | 5.6k |
| Last analyzed | Oct 3, 2026 | Oct 25, 2026 |
Key differences
- fastapi derives validation and OpenAPI schemas from Python type hints and Pydantic models; tornado defines applications with URL routes and request handlers.
- fastapi supports synchronous and asynchronous endpoints; tornado centers on non-blocking I/O and asyncio integration for many open connections.
- fastapi includes interactive documentation with Swagger UI and ReDoc; tornado emphasizes long polling and WebSockets.
- fastapi is licensed under MIT; tornado is licensed under Apache-2.0.
- fastapi's stated use cases include REST APIs and nested JSON payloads; tornado's include real-time services that keep client connections open.
- tornado's project notes report no releases in over a year and concentrated contributor activity; fastapi's repository is not archived.
Choose fastapi if you…
- need typed API definitions with validation and data conversion.
- want OpenAPI output and interactive API documentation derived from endpoint definitions.
- build REST services that benefit from Pydantic models and synchronous or asynchronous endpoints.
Choose tornado if you…
- need to keep many client connections open using non-blocking I/O.
- build long-polling or WebSocket applications such as chat or messaging services.
- want web request handling and asynchronous networking tools in one Python framework.
Compare the numbers side by side, or add more projects
This comparison is generated with AI from the OSRepos analyses of both projects. Always check each project's repository and documentation before choosing.