FastAPI vs Django

FastAPI and Django are the two Python frameworks most teams compare when starting a backend in 2026. FastAPI is an async API layer built on type hints, and Django is a full application framework that includes its own ORM and admin. Picking one decides how much you assemble yourself and how the codebase looks after a year of growth.

The main differences:

• FastAPI is ASGI and async-first, while Django supports async views on top of a mostly synchronous ecosystem.
• FastAPI validates requests from Pydantic models in the handler signature, while Django validates through forms or Django REST framework serializers.
• Django ships an ORM, migrations, auth and an admin, while FastAPI leaves data access to libraries you choose.
• FastAPI generates OpenAPI docs from your types, while Django needs DRF or django-ninja for that.

FastAPI vs Django at a glance

FastAPI: async APIs from type hints

FastAPI reads the handler signature to parse and validate input, then generates an OpenAPI schema and interactive docs from the same types. Handlers can be async def and await database and network calls, which the FastAPI async guide explains along with when plain def is the better choice.

import os
from contextlib import asynccontextmanager

import asyncpg
from fastapi import FastAPI, Request
from pydantic import BaseModel


class Signup(BaseModel):
    email: str


@asynccontextmanager
async def lifespan(app: FastAPI):
    app.state.pool = await asyncpg.create_pool(os.environ["DATABASE_URL"])
    yield
    await app.state.pool.close()


app = FastAPI(lifespan=lifespan)


@app.post("/users", status_code=201)
async def create_user(req: Signup, request: Request) -> dict:
    await request.app.state.pool.execute(
        "INSERT INTO users (email) VALUES ($1)", req.email
    )
    return {"email": req.email}

FastAPI does not include an ORM or a migration tool. Teams usually add SQLAlchemy with Alembic, SQLModel or a driver such as asyncpg directly, and auth comes from security utilities plus a library of your choosing.

Django: the application framework

Django gives you models, migrations, sessions, auth and the Django admin, which generates a management UI from your models. For JSON APIs most projects add Django REST framework or django-ninja.

import json

from django.db import models
from django.http import HttpRequest, JsonResponse
from django.views.decorators.csrf import csrf_exempt
from django.views.decorators.http import require_POST


class User(models.Model):
    email = models.EmailField(unique=True)


@csrf_exempt
@require_POST
def create_user(request: HttpRequest) -> JsonResponse:
    email = json.loads(request.body)["email"]
    user = User.objects.create(email=email)
    return JsonResponse({"id": user.pk, "email": user.email}, status=201)

Django has supported async views since 3.1, and the ORM has async methods such as acreate. The Django async documentation notes that transactions do not yet work in async mode, so code that needs them runs as a synchronous function wrapped with sync_to_async.

Performance and concurrency

Both frameworks can run on an ASGI server, which the ASGI specification defines as the async successor to WSGI. FastAPI benefits more because its handlers and common libraries are async end to end. A Django app with synchronous views scales by adding worker processes. In both cases the database is usually the bottleneck before the framework is.

Adding infrastructure to either framework with Encore

Encore combines the framework you chose with infrastructure declared in Python. It is an infrastructure SDK installed as encore-dev, and FastAPI or Django keeps routing and request handling. Postgres databases, Pub/Sub topics, object storage buckets, cron jobs and secrets become module-level declarations that Encore discovers and provisions.

With FastAPI, the signup handler writes to a declared database and publishes an event, and encore.start() in the lifespan hook starts the subscriptions:

from contextlib import asynccontextmanager

import encore
from encore import pubsub
from encore.storage import postgres
from fastapi import FastAPI
from pydantic import BaseModel

db = postgres.Database("users", migrations="./migrations")


class Signup(BaseModel):
    email: str


signups = pubsub.Topic[Signup]("signups")


async def send_welcome(message: pubsub.Message[Signup]) -> None:
    print("welcome", message.data.email)


welcome = pubsub.Subscription[Signup](signups, "send-welcome", handler=send_welcome)


@asynccontextmanager
async def lifespan(app: FastAPI):
    await encore.start()
    yield


app = FastAPI(lifespan=lifespan)


@app.post("/users", status_code=201)
async def create_user(req: Signup) -> dict:
    row = await db.query(
        "INSERT INTO users (email) VALUES ($1) RETURNING id", req.email
    ).first()
    await signups.publish(req)
    return {"id": row["id"] if row else None}

With Django, the ORM keeps working as before. settings.py reads the connection string from the declared database, and Django manages the schema through its own migrations:

from psycopg.conninfo import conninfo_to_dict

from encore.storage import postgres

db = postgres.Database("app")

connection = conninfo_to_dict(db.connection_string)
DATABASES = {
    "default": {
        "ENGINE": "django.db.backends.postgresql",
        "NAME": connection.pop("dbname"),
        "USER": connection.pop("user", ""),
        "PASSWORD": connection.pop("password", ""),
        "HOST": connection.pop("host", ""),
        "PORT": connection.pop("port", ""),
        "OPTIONS": connection,
    }
}

encore run starts Postgres locally along with the topics and buckets, and the CLI also runs Django management commands through encore exec so they get the same configuration. Cron jobs do not run locally or in preview environments.

A deploy provisions the same declarations in your own AWS or GCP account.

An agent that adds a topic to a Django view writes the declaration in the same diff, and the change runs locally before review. Cloud access sits with Encore's IAM role, not the agent. The AI integration guide covers the rules files that teach an agent these conventions.

Python support is in beta, and you can request access.

Try Encore →

How to choose

• FastAPI for JSON APIs with async I/O and type-hint validation.
• Django for relational apps that need an admin and auth from day one.

Either choice works with Encore when you want databases and queues running locally and provisioned in your own cloud account.

Related guides

• FastAPI vs Django vs Flask
• Deploy FastAPI to AWS
• Best Python backend frameworks in 2026
• How to add Postgres to a FastAPI app
• How to add Postgres to a Django app
• Best Python backend framework for AI coding agents
• Best Python framework for building AI agents