When comparing ASP.NET Core vs FastAPI, the Slant community recommends FastAPI for most people. In the question“What are the best backend web frameworks?” FastAPI is ranked 4th while ASP.NET Core is ranked 6th. The most important reason people chose FastAPI is:
It has a simple but powerful dependency injection system, it can be used to handle authentication, per-user rate limiting, authorization controls (e.g. with roles), etc.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Fast and getting faster
Thanks to breakthroughs in ROSLYN compiler and the efforts of the .NET COre developer team, code written in C# can reach speeds just a step behind C++.
Pro Multi platform
Can run on Windows, Linux and Mac (also Visual Studio Code editor).
Pro JSON optimization
In .NET Core 2.1 and 3.0, new APIs are added that make it possible to write JSON APIs that require less memory, using Span<T> and UTF8 strings, and improve throughput of applications like Kestrel, ASP.NET Core web server. See also Utf8JsonReader.
Pro Tutorials and documentation quality
Both microsoft and 3rd party tutorials are mostly of high quality and encourage you to use the industry best-practices.
Pro Built-in middleware
Built-in middleware featuring: Authentication, Cookie policy, Health Check, MVC, Session etc.
Pro Hosting
Ability to host on IIS, Nginx, Apache, Docker, or self-host in your own process.
Pro Ease of Use
Pro Security
It is a very secure platform.
Pro Tooling
Both VS and VSCode are powerful free IDEs that are well integrated with ASP.net Core. VS Community also allows for commercial use for projects with less than 5 developers.
Pro Dependency injection
It has a simple but powerful dependency injection system, it can be used to handle authentication, per-user rate limiting, authorization controls (e.g. with roles), etc.
Pro Standards
It is based on standards: OpenAPI, JSON Schema and OAuth 2.0.
Pro Data validation
It validates the data using the types you declared. Even in deeply nested JSON requests.
Pro High-performance
It's based on Starlette and Pydantic, so, it's one of the fastest Python frameworks.
Pro Editor completion
It is based on Python type declarations, so, editors and tools can give great support. Including type checks and autocompletion everywhere.
Pro One of the fastest growing communities
Pro Fast is really fast (!)
It's easy to develop API based applications in Python on deadlines for Android and IOS Development.
Pro Automatic docs
It generates interactive API documentation automatically from your code.
Pro Database independent
It's independent of database or ORM, but compatible with all of them. Including relational databases and NoSQL.
Pro Async IO / optional
It's based on Async IO, which gives it high concurrency. But you can use non-async libraries and it runs them appropriately.
Pro World class documentation
It has some of the best documentation of any framework.
Pro WebSockets
Because it's an async framework, it can handle async-native protocols like WebSockets.
Pro OAuth 2.0
It has integrated support for OAuth 2.0. Including declaring required scopes per endpoint. So, you can easily integrate it with external OAuth 2.0 providers or build your own with it.
Pro Background tasks
Included support for background tasks, thanks to being based on Starlette.
Pro Supports GraphQL
Python's graphene library is included as an optional dependency meaning that GraphQL API's are supported out of the box, with no additional tweaking needed.
Cons
Con Microsoft environment
Con Smaller community
Since FastAPI is relatively new, its community is smaller than Django Rest Framework. But it can grow with time.