Django vs Flask: A Detailed Comparison

Django and Flask are two of the most popular web frameworks in Python. While both are used to build web applications, they differ in architecture, features, and use cases. Below is a detailed comparison between Django and Flask.

1. Overview

Feature	Django	Flask
Type	Full-stack web framework	Micro-framework
Architecture	Model-View-Template (MVT)	Flexible, minimal
Flexibility	Less flexible, follows a structured approach	Highly flexible, minimal structure
Built-in Features	Admin panel, authentication, ORM, and more	Only basic routing and request handling
Scalability	Suitable for large, complex applications	Suitable for small to medium projects
Learning Curve	Steeper due to many built-in features	Easier for beginners
Performance	Slightly slower due to built-in features	Faster due to minimal overhead

2. Installation

Django Installation

pip install django
django-admin startproject myproject

Flask Installation

pip install flask

3. Project Structure

Django Structure (Auto-Generated)

myproject/
│── manage.py
│── myproject/
    │── __init__.py
    │── settings.py
    │── urls.py
    │── wsgi.py
│── myapp/
    │── models.py
    │── views.py
    │── urls.py

Django enforces a well-structured format.

Flask Structure (Manually Defined)

myflaskapp/
│── app.py
│── templates/
│── static/

Flask provides flexibility to organize files as needed.

4. Routing

Django Routing (urls.py)

from django.urls import path
from myapp import views

urlpatterns = [
    path('', views.home, name='home'),
]

Flask Routing (app.py)

from flask import Flask

app = Flask(__name__)

@app.route('/')
def home():
    return "Welcome to Flask!"

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

Flask’s routing is simpler and defined within the same file.

5. Database Handling

Django ORM (Object-Relational Mapping)

Django provides a built-in ORM to interact with databases.

from django.db import models

class Student(models.Model):
    name = models.CharField(max_length=100)
    age = models.IntegerField()

Migrations:

python manage.py makemigrations
python manage.py migrate

Flask with SQLAlchemy

Flask does not come with ORM, but SQLAlchemy can be used.

from flask_sqlalchemy import SQLAlchemy

app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///students.db'
db = SQLAlchemy(app)

class Student(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(100))
    age = db.Column(db.Integer)

Migrations:

from app import db
db.create_all()

Django’s ORM is built-in, while Flask relies on third-party extensions.

6. Template Engine

Both Django and Flask use Jinja2 as their default template engine.

Django Template

{% for student in students %}
    <p>{{ student.name }}</p>
{% endfor %}

Flask Template

htmlCopyEdit{% for student in students %}
    <p>{{ student.name }}</p>
{% endfor %}

The syntax is the same, but Django provides more built-in template filters.

7. Authentication & Security

Django Authentication (Built-in)

from django.contrib.auth.models import User

user = User.objects.create_user(username='john', password='123')

Django has built-in authentication, session management, and security features.

Flask Authentication (Third-Party)

Flask requires extensions like Flask-Login for authentication.

from flask_login import LoginManager

login_manager = LoginManager()
login_manager.init_app(app)

Django is more secure by default, while Flask requires additional configuration.

8. Admin Panel

Django Admin Panel (Auto-Generated)

from django.contrib import admin
from myapp.models import Student

admin.site.register(Student)

Run:

python manage.py createsuperuser

Access at: http://127.0.0.1:8000/admin/

Flask Admin (Third-Party)

Flask does not include an admin panel but supports Flask-Admin.

from flask_admin import Admin
admin = Admin(app)

Django provides a ready-to-use admin panel, while Flask needs extra setup.

9. REST API Development

Django REST Framework (DRF)

bashCopyEditpip install djangorestframework

from rest_framework import serializers
from myapp.models import Student

class StudentSerializer(serializers.ModelSerializer):
    class Meta:
        model = Student
        fields = '__all__'

Django REST Framework makes API development easier.

Flask with Flask-RESTful

pip install flask-restful

pythonCopyEditfrom flask_restful import Resource, Api

api = Api(app)

class StudentAPI(Resource):
    def get(self):
        return {'name': 'John'}

api.add_resource(StudentAPI, '/students')

Django REST Framework is more feature-rich compared to Flask-RESTful.

10. Performance & Scalability

Django: Slightly slower due to its heavy built-in features.
Flask: Faster and lightweight but requires additional setup for large applications.

For high-performance applications, Flask is preferable.

11. Use Cases

Use Case	Django	Flask
Large enterprise applications	Yes	No
Simple web applications	No	Yes
REST APIs	Yes	Yes
Admin dashboards	Yes	No
Custom web applications	No	Yes
Rapid development	Yes	No

Django is ideal for large applications, while Flask is better for small to medium projects.

12. Deployment

Django Deployment

Use Gunicorn & Nginx:

pip install gunicorn
gunicorn myproject.wsgi

Flask Deployment

Use Gunicorn:

gunicorn -w 4 app:app

Both frameworks support deployment on Heroku, AWS, and Docker.

13. Pros & Cons

Django Pros

✅ Built-in admin panel
✅ Secure by default
✅ Rich ecosystem of features

Django Cons

❌ Steeper learning curve
❌ Slower due to built-in features

Flask Pros

✅ Lightweight and flexible
✅ Faster performance
✅ Easier for beginners

Flask Cons

❌ Requires third-party extensions
❌ No built-in admin panel

14. When to Choose Django vs Flask

Choose Django If:	Choose Flask If:
You need built-in features	You need a lightweight framework
You’re building a large project	You want full control over structure
Security is a major concern	You prefer minimalism