Django or FastAPI: which Python framework to choose for a web project

Choose Django for a product with an admin panel, users, roles and lots of standard features: it provides all of this out of the box and lets you build a complete service quickly. Choose FastAPI for API services, integrations and AI backends where async I/O, strict typing and automatic documentation matter. Both are mature; the type of project decides, not speed.

Here is how the frameworks differ and when each one pays off.

How does Django differ from FastAPI?

Django is a batteries-included framework: ORM, migrations, admin, authentication, forms, templates and protection from common attacks. FastAPI is a lightweight API framework built on Python type hints: it validates input, generates OpenAPI documentation and is async from the ground up, while everything else is added separately.

Criterion	Django	FastAPI
Approach	Batteries included	A minimal core for APIs
ORM and migrations	Built in	Separate: SQLAlchemy, SQLModel and others
Admin panel	Built in, configured in hours	None; build or add one
Data validation	Forms and DRF serializers	Pydantic based on Python types
API documentation	Via extra packages	Generated automatically
Async	Supported, but historically synchronous	Async from the start
Best suited to	Products with dashboards and admin	API services, integrations, AI backends

What does Django and FastAPI code look like?

Code shows the difference in approach: in Django, the model, migrations and admin appear almost on their own; in FastAPI, the endpoint's input and output definitions take centre stage.

# Django: a model plus admin registration — the table, migration and management UI are ready
class Order(models.Model):
    customer = models.ForeignKey(Customer, on_delete=models.PROTECT)
    total = models.DecimalField(max_digits=12, decimal_places=2)
    status = models.CharField(max_length=20, default="new")

admin.site.register(Order)

# FastAPI: an endpoint with input validation and automatic documentation
class OrderIn(BaseModel):
    customer_id: int
    total: Decimal = Field(gt=0)

@app.post("/orders", status_code=201)
async def create_order(data: OrderIn, db: AsyncSession = Depends(get_db)) -> OrderOut:
    order = await orders.create(db, data)
    return OrderOut.model_validate(order)

Photo: Unsplash

When should you choose Django?

Choose Django when the product is a full web application with users, roles, an admin panel and many entities: CRMs, internal systems, marketplaces, learning platforms, content sites. The built-in admin saves weeks of development and lets the business work with data from day one.

Signs Django fits:

• managers and operators need an admin panel;
• many related entities and standard flows: sign-up, roles, forms;
• speed to the first release matters;
• the team values conventions and a ready project structure.

For APIs, Django is usually paired with Django REST Framework — a mature library with serializers, permissions and pagination.

When should you choose FastAPI?

Choose FastAPI for services that mostly send and receive data: an API for a mobile app, an integration layer, a service calling AI models or external APIs, where async I/O lets it wait on many requests at once efficiently.

Where FastAPI shines:

1. Backends for AI features: model calls and document retrieval — we described such a service in RAG: build an AI assistant on your documents.
2. A microservice with a clear API alongside a main application on another stack.
3. Integrations that spend a lot of time waiting on external services.
4. Projects where strict typing and API docs matter without extra effort.

What to keep in mind with FastAPI

FastAPI's freedom means you choose and assemble project structure, database access, migrations, authentication and an admin panel yourself. For a small service that is a plus; for a large product with dashboards and admin, it means extra weeks of work.

How do you choose for your project?

Choose by what makes up most of the product: interfaces for people and data management point to Django; APIs and integrations point to FastAPI. They are often combined: the main product in Django, a separate service for AI or a high-load API in FastAPI.

Questions to decide:

• Do staff need an admin panel?
• How many entities and standard flows does the product have?
• Will there be long calls to external services and models?
• What is the team's experience, and how important is launch speed?

A similar choice on Node.js is covered in NestJS vs Express: the same trade-off between ready structure and freedom.

In short

• Django is batteries included: ORM, migrations, admin, auth — for products with dashboards and admin.
• FastAPI is a lightweight async API framework with type-based validation and docs.
• FastAPI suits AI backends and integrations; Django suits CRMs and marketplaces.
• They can be combined: the main product in Django, separate services in FastAPI.
• The type of project decides, not framework speed.