# FastAPI 49 Hacker News commenters recommended FastAPI and 22 criticized it, November 2025 to November 2026. It was recommended in 12 of 13 months. It meets the Hacker Approved badge rule. **Verdict:** Developers recommend it as an easy, flexible Python framework for web APIs, with automatic OpenAPI docs and type validation via Pydantic. Critics point to async complexity. ## Why people recommend it - Automatic OpenAPI and JSON schema validation (3 comments): "their OpenAPI generation isn't always perfect if you have very polymorphic endpoints but it is really good compared to other tools" ([source](https://news.ycombinator.com/item?id=48183473)) "I'm beginning to come round to the benefits of OpenAPI now which seems like a big note in FastAPI's favor" ([source](https://news.ycombinator.com/item?id=47497090)) "auto enforcing json schemas on endpoints is huge" ([source](https://news.ycombinator.com/item?id=45802961)) - Pydantic-based typing that works well (4 comments): "the hard work that the original designers of libraries like FastAPI, Zod, Pydantic, have invested in" ([source](https://news.ycombinator.com/item?id=47436413)) "Pydantic + FastAPI are my two favorite python shops right now" ([source](https://news.ycombinator.com/item?id=46919607)) "The agent uses Pydantic for validating FastAPI schemas" ([source](https://news.ycombinator.com/item?id=48145069)) - Easy and flexible to build with (3 comments): "FastAPI is the best combination of an easy and a flexible Python library for web servers, from my experience." ([source](https://news.ycombinator.com/item?id=46060596)) "I chose FastAPI and Pydantic specifically to give that same "get out of my way" developer experience" ([source](https://news.ycombinator.com/item?id=46612037)) "making those rapid iterations that tools like fastapi allow can be pretty important" ([source](https://news.ycombinator.com/item?id=46053658)) - Known, stable library with thriving ecosystem (3 comments): "fastapi was picked simply because it was already known by the team and had a very thriving ecosystem" ([source](https://news.ycombinator.com/item?id=49604149)) "Backend API Python with FastAPI, well known and stable library" ([source](https://news.ycombinator.com/item?id=47750670)) "Python with FastAPI, well known and stable library" ([source](https://news.ycombinator.com/item?id=47824487)) ## What people warn about - Async adds complexity and easy mistakes (2 comments): "FastAPI is operating more at that level but also adds the often unnecessary complexity of async." ([source](https://news.ycombinator.com/item?id=48442158)) "it’s so easy to screw up async FastAPI and bring things to a halt." ([source](https://news.ycombinator.com/item?id=45805969)) - Slow under load, CPU work blocks (4 comments): "René actually had to implement a batching worker API to work around a limitation in Python's FastAPI, which handled requests per process" ([source](https://news.ycombinator.com/item?id=45887037)) "in any meaningful benchmark it's one of the slowest commercially used pieces of web software the industry has adopted" ([source](https://news.ycombinator.com/item?id=46060155)) "The performance gains are lost, by double when you attempt to build real real software with it." ([source](https://news.ycombinator.com/item?id=46169791)) - Bare-bones, many features built yourself (3 comments): "things hang together much more loosely and it means the integration just isn't as complete" ([source](https://news.ycombinator.com/item?id=46154958)) "finding a lot of that is build-it-yourself (and easily break it) is a bit of a shock." ([source](https://news.ycombinator.com/item?id=46796433)) "FastAPI+Unicorn is good but it is barebones compared to what django already has." ([source](https://news.ycombinator.com/item?id=45814041)) - Per-request database and dependency design (3 comments): "FastAPI encourages you to open a db connection and a transaction at the front of every request" ([source](https://news.ycombinator.com/item?id=48769720)) "by suggesting using dependency injection to manage database connections" ([source](https://news.ycombinator.com/item?id=49011319)) "it also constructs dependencies per request instead of singletons" ([source](https://news.ycombinator.com/item?id=46419909)) ## Alternatives hackers recommend - [Ruby on Rails](https://hackerapproved.com/p/ruby-on-rails.md): 337 recommend - [Django](https://hackerapproved.com/p/django.md): 277 recommend - [Next.js](https://hackerapproved.com/p/next-js.md): 127 recommend - [Phoenix Framework](https://hackerapproved.com/p/phoenix.md): 85 recommend - [Laravel](https://hackerapproved.com/p/laravel.md): 71 recommend ## Cite as Hacker Approved, "FastAPI", https://hackerapproved.com/p/fastapi/ (counts from 1,795,640 Hacker News comments, November 2025 to November 2026).