fastapi vs air
Python frameworks for APIs and web pages compared
fastapi builds HTTP APIs around Python type hints, using them for validation, data conversion, and OpenAPI documentation. air builds on FastAPI to combine server-rendered HTML pages and API routes in one application, with typed HTML elements, Jinja, and HTMX utilities.
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.
air: Build Python Web Apps with HTML and FastAPI
Air is a Python web framework for building HTML pages alongside FastAPI APIs. It offers typed Python HTML elements, Jinja templates, and HTMX utilities, with an API designed to be clear to both developers and AI coding assistants.
| fastapi | air | |
|---|---|---|
| Language | Python | Python |
| License | MIT | MIT |
| Stars | 103k | 920 |
| Forks | 10k | 100 |
| Last analyzed | Oct 3, 2026 | Oct 3, 2026 |
Key differences
- fastapi focuses on HTTP APIs, while air targets applications that combine HTML pages and API endpoints.
- fastapi uses type annotations to describe API inputs and outputs; air adds page routes, typed HTML classes, and Jinja rendering.
- air is built on FastAPI and Pydantic, and can use FastAPI capabilities such as OpenAPI documentation and WebSockets alongside pages.
- fastapi supports synchronous and asynchronous endpoints; air’s listed focus is server-rendered pages and APIs in one app.
- air is identified as alpha, with possible API changes between releases; fastapi’s listed considerations do not include that warning.
- Both are Python projects licensed under MIT, and neither repository is archived.
Choose fastapi if you…
- need a framework focused on HTTP APIs with validation and OpenAPI documentation derived from type annotations.
- want synchronous or asynchronous API endpoints, with support for dependency injection, security integrations, or WebSockets.
- prefer working directly with FastAPI’s Starlette and Pydantic foundations.
Choose air if you…
- want server-rendered HTML pages and API routes in one Python application.
- need typed Python HTML elements, Jinja templates, or HTMX utilities alongside FastAPI capabilities.
- are comfortable using an alpha project whose APIs may change between releases.
This comparison is generated with AI from the OSRepos analyses of both projects. Always check each project's repository and documentation before choosing.