🚀 𝗙𝗮𝘀𝘁𝗔𝗣𝗜 𝘃𝘀 𝗙𝗹𝗮𝘀𝗸 - 𝗠𝘆 𝗛𝗼𝗻𝗲𝘀𝘁 𝗟𝗲𝗮𝗿𝗻𝗶𝗻𝗴 𝗘𝘅𝗽𝗲𝗿𝗶𝗲𝗻𝗰𝗲 I've worked with Flask before, and recently I started learning FastAPI. At first, I thought both are kind of similar… but while practicing, I started noticing some real differences. Let me explain in simple words 🔹 𝗙𝗹𝗮𝘀𝗸 (𝗦𝘆𝗻𝗰𝗵𝗿𝗼𝗻𝗼𝘂𝘀) Flask works in a step-by-step way. It means if one request is being processed, the next one has to wait. It uses WSGI (Werkzeug) and is very simple to start with. But the downside is, you have to handle many things manually like validation and API documentation. 🔹 𝗙𝗮𝘀𝘁𝗔𝗣𝗜 (𝗔𝘀𝘆𝗻𝗰𝗵𝗿𝗼𝗻𝗼𝘂𝘀) FastAPI works in a smarter way. It can handle multiple requests at the same time without making others wait. It uses ASGI (built on Starlette) and supports async programming. It also provides built-in validation using Pydantic and automatically generates interactive API docs (Swagger UI). ⚙️ 𝗦𝗲𝗿𝘃𝗲𝗿𝘀 Flask is commonly used with Gunicorn FastAPI is commonly used with Uvicorn (ASGI server) 💡 𝗦𝗶𝗺𝗽𝗹𝗲 𝗗𝗶𝗳𝗳𝗲𝗿𝗲𝗻𝗰𝗲 Synchronous → one task at a time (wait and then move) Asynchronous → handle multiple tasks together (no waiting) 💡 𝗠𝘆 𝗧𝗮𝗸𝗲𝗮𝘄𝗮𝘆 Flask is great for beginners and small projects. But FastAPI feels more modern, faster, and very useful for scalable apps, especially in AI/ML projects where performance matters. I am still learning FastAPI, but so far, it feels really powerful and clean to work with 🔥 𝗪𝗵𝗮𝘁 𝗱𝗼 𝘆𝗼𝘂 𝗽𝗿𝗲𝗳𝗲𝗿 - 𝗙𝗹𝗮𝘀𝗸 𝗼𝗿 𝗙𝗮𝘀𝘁𝗔𝗣𝗜? #FastAPI #Flask #Python #BackendDevelopment #WebDevelopment #APIs #MachineLearning #AI #SoftwareDevelopment #LearningJourney
Great Comparison, just a small not, flask actually supports async handler since v2.0 and pydantic validation can be used with flask since it's just a package,!
One more thing to add! While Flask is traditionally synchronous, since Flask 2.0 it does support async/await syntax, so you can write async routes as well. However, FastAPI still has an edge for high-performance apps because it’s built as a native ASGI framework from the ground up, whereas Flask’s async support is more limited in comparison. For me, FastAPI feels like a better fit for modern APIs, but it’s great to see Flask evolving too...