Django vs FastAPI

Both are popular Python web frameworks, but they target different problems. Django is a full-stack framework for building complete web applications. FastAPI is a lean API framework optimized for building RESTful services and microservices with automatic validation and docs.

Comparison

	Django	FastAPI
Type	Full-stack web framework	API-first framework
Primary use case	Server-rendered sites, admin panels, CRUD apps	REST APIs, microservices, async I/O workloads
ORM	Built-in Django ORM	None built-in (SQLAlchemy, Tortoise, etc.)
Admin panel	Built-in automatic admin	Not included
Templates	Built-in template engine	Not included (returns JSON by default)
Validation	Forms, serializers (DRF), manual checks	Automatic via Pydantic type hints
API documentation	Requires Django REST Framework or third-party tools	Auto-generated Swagger UI and ReDoc
Async support	Added in Django 3+ (views, ORM still evolving)	Native async/await from the start
Performance	Good for traditional web apps	Very fast — Starlette + Uvicorn ASGI stack
Learning curve	Steeper — many built-in concepts (apps, migrations, settings)	Lower for API-only projects
Testing	Extends Python unittest	Works with pytest; TestClient for HTTP tests
Run command	`python manage.py runserver`	`fastapi dev main.py`

When to Use

Choose Django when…	Choose FastAPI when…
You need a full website with HTML pages, user auth, and an admin panel. You want batteries-included tooling (ORM, migrations, forms). You are building a monolithic web application.	You are building a REST or GraphQL API consumed by a frontend or mobile app. You need high throughput, async endpoints, or microservices. You want automatic OpenAPI docs and request validation out of the box.

Minimal Hello World

Django


# views.py
from django.http import JsonResponse

def hello(request):
    return JsonResponse({"message": "Hello World"})

FastAPI


from fastapi import FastAPI

app = FastAPI()

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