Comparison of FastAPI with Django and Flask

For starters, as you may know, Python is an interpreted programming language that is becoming more and more popular for building web applications. However, there are numerous web frameworks to choose from but they all have different use cases. In this article, we will look at 3 frameworks which are :

1. Django – It follows the model-template-view architectural pattern and a DRY principle (Don’t Repeat Yourself).
2. Flask – This is based on the Werkzeug WSGI toolkit and Jinja2 template engine.
3. FastAPI – It is a micro-web-framework based on Pydantic and type hints.

After reading this article, you’ll be able to compare these frameworks based on various factors like Efficiency, Readability, Use Case, etc. which should help you make a better choice for your web application.

What is Django?

Django is an open-source full-stack web framework written in Python that follows the MTV (model-template-view) architectural pattern and a DRY principle (Don’t Repeat Yourself). It was made by Adrian Holovaty and Simon Willison and was publicly published in 2005. The name given is based on the singer Django Reinhardt. For more information regarding Django, you can read this article.

What is Flask?

Flask is an open-source beginner-friendly micro-web framework written in Python that follows the MVC (model-view-controller) architectural pattern and supports Jinja templates, which can be used to create views. It was made by Armin Ronacher of Pocoo, an international group of Python enthusiasts formed in 2004. The name “Flask” is a reference to the earlier Bottle framework. For more information regarding Flask, you can read this article.

What is FastAPI?

FastAPI is also an open-source Starlette-ASGI (Asynchronous Server Gateway Interface) micro-web framework written in Python used to create RESTful APIs. It was made by Sebastián Ramírez in December 2018. The name is based on the speed to develop API hence ‘FastAPI’. For more information regarding Flask, you can read this article.

Comparison Between FastAPI vs Django

Parameters	Django	FastAPI	Flask
Type	Full-stack web framework	Micro-web framework	Micro-web framework
Use Case	Build complex web applications & APIs	Build APIs & Microservices	Ideal for building small web applications and simple APIs
Performance	Fast for building large web application	Very Fast for building APIs and Microservices	Slower because of manual validation and synchronized programming.
Scalability	Scalable but it’s ORM and template engine can make it slower to scale	Highly Scalable, as it uses asynchronize code and type annoations.	Difficult to scale as there is no in-built support for ORM or caching.
Learning Curve	Complex for beginners	Simple for beginners	Moderate for beginners
Database Tools	Comprehensive set	Limited, no built-in support	Limited, no built-in support
Asynchronous Programming	Yes, can be done with help of Asyncio but little slower.	Yes, but faster beacuse of Pydantic.	No, but can we done using other libraries.
ORM (Object-relational mapping)	Yes	No	No
Community	Large and active	Small but growing	Large and active
Documentation	Huge	Small but still growing	Big
Advantages	It is a great choice who want to build web applications that are secure, scalable, flexible, and easy to maintain	It is a great choice for building fast performance APIs and microservices	It is a great choice to build small to medium level web application and where performance is not much of a issue and developer need flexibility.
Disadvantages	It can be Complex for beginners, hard to debug and not suitable for small projects	Main files can we crowdy and lack of built-in security.	No built-in support for caching, ORM, asynchronization, etc

Basic Code: FastAPI

Let’s compare same code in different frameworks.

Example: Here is a simple example of how to create a GET endpoint in FastAPI:

Python3

from fastapi import FastAPI

app = FastAPI()

@app.get("/")
def hello():
    return {"Hello": "World"}

Asynchronize Code using FastAPI:

Python3

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def hello():
    return {"Hello": "World"}

Basic Code: Flask

Example: Here is the same example in Flask

Python3

from flask import Flask

app = Flask(__name__)


@app.route("/", methods=["GET"])
def hello():
    return "Hello World"


if __name__ == '__main__':
    app.run(debug=True)

Basic Code: Django

Example: Here is the same example in Django.

myapp/views.py

Python3

from django.http import HttpResponse

def hello(request):
    return HttpResponse("Hello World")

myapp/urls.py

Python3

from django.urls import path

from .views import home_page_view

urlpatterns = [
    path("", hello, name="home"),
]

myproject/urls.py

Python3

from django.contrib import admin
from django.urls import path, include

urlpatterns = [
    path("admin/", admin.site.urls),
    path("", include("pages.urls")),
]

Output: Output for all the frameworks will be the same; the port number will differ according to the framework.

Framework	Default Port Number
FastAPI	8000
Flask	5000
Django	8000

Also, the creation and execution of your file will differ according to the framework.

FastAPI

FastAPI

Flask

Flask

Django

Django

Conclusion

Therefore now we can conclude that we can use FastAPI for its high performance in API development, Flask can be used to build small to medium projects with great flexibility, and Django to build feature-rich, large-scale applications.