FastAPI vs Sanic
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
A Python framework for building web APIs quickly, using standard type hints.
Open source · MIT
A Python web framework for building fast asynchronous web apps and APIs.
The short answer
Choose FastAPI if you need…
- Python developers building JSON APIs or back-end services
- Teams that want automatic interactive API docs from their code
- ML teams serving model predictions over HTTP, as several cited examples do
- Developers who already use Python type hints and want less boilerplate
Choose Sanic if you need…
- Python developers building web APIs or backend services
- Teams that want an asyncio-based Python web framework
- Developers who prefer an ASGI-compatible Python stack
Side-by-side
| FastAPI | Sanic | |
|---|---|---|
| Type | Library | Framework |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 105k | 18.6k |
| Setup difficulty | Beginner | Intermediate |
| How you get it | Install with a package manager | Install with a package manager |
| Main language | Python | Python |
| Last code update | 4 days ago | 3 months ago |
What each one is
FastAPI
FastAPI is a Python framework for building web APIs, the back-end services that apps and websites use to send and receive data. You define your endpoints with standard Python type hints, and FastAPI uses them to validate input and generate interactive API documentation automatically. It is built on Starlette for the web layer and Pydantic for data handling.
Sanic
Sanic is an open-source Python framework for building web applications and API servers. It is built around asynchronous programming (asyncio), which lets one process handle many requests at once. Its description emphasizes speed, though the README provided here was empty, so details beyond the project metadata could not be verified.
Best for
FastAPI
- Python developers building JSON APIs or back-end services
- Teams that want automatic interactive API docs from their code
- ML teams serving model predictions over HTTP, as several cited examples do
- Developers who already use Python type hints and want less boilerplate
Sanic
- Python developers building web APIs or backend services
- Teams that want an asyncio-based Python web framework
- Developers who prefer an ASGI-compatible Python stack
Strengths
FastAPI
- Uses standard Python type hints for validation and editor autocompletion
- Generates OpenAPI and JSON Schema documentation automatically
- Released under the permissive MIT license with a large community (over 100k GitHub stars)
Sanic
- MIT license, permissive for commercial and personal use
- Active project with a recent release (v25.12.1) and a recent push
- Uses asyncio and ASGI, standard tools in modern Python web development
Not ideal for
FastAPI
- People who need a full-stack web framework with built-in templates and admin panels, since FastAPI focuses on APIs
- Non-Python teams, because the framework is written for Python
- Beginners with no Python background, since it assumes familiarity with type hints and async concepts
Sanic
- Complete beginners with no Python experience, since writing web servers requires comfort with the language
- Projects that need a full batteries-included framework with built-in admin panels, because the README provided no evidence of such features
- Anyone needing verified performance numbers, since none were available in the supplied README
Trade-offs
FastAPI
- The README's speed and productivity figures are the authors' own estimates and are not independently verified here
- Scope is limited to APIs, so you will add other libraries for things like templating or database access
- Advanced async behavior requires understanding Python's async model
Sanic
- The supplied README was empty, so features and setup steps are not verified here
- Requires familiarity with asynchronous Python, which has a learning curve
- Speed claims come from the project description and were not independently verified
Getting started
FastAPI
Add FastAPI to a project with uv
uv add "fastapi[standard]"Frequently asked questions
What is the difference between FastAPI and Sanic?
FastAPI: A Python framework for building web APIs quickly, using standard type hints. Sanic: A Python web framework for building fast asynchronous web apps and APIs. FastAPI suits python developers building json apis or back-end services, while Sanic suits python developers building web apis or backend services.
Are FastAPI and Sanic free?
FastAPI: Free and open source. Sanic: Free and open source.
Which is easier to set up, FastAPI or Sanic?
FastAPI is easier to get started with (rated beginner); Sanic is rated intermediate and usually needs more setup.
Is FastAPI or Sanic more popular?
FastAPI has more GitHub stars (105k) than Sanic (18.6k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to FastAPI and Sanic?
Other options people compare them with include Redoc, Dear ImGui, peewee, Phoenix.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.