Which Is the Best Python Web Framework: Django, Flask, or FastAPI?

When it comes to building robust Python web applications, Django, Flask, and FastAPI stand as the most popular choices. According to the JetBrains Python Developer Survey 2024, these three frameworks remain the most desired choice for developers in backend development. While Django delivers a secure and full-featured web development solution, Flask, the micro-framework, provides lightweight flexibility and control, and FastAPI offers modern, high-performance capabilities ideal for developing fast and scalable APIs.

For businesses, choosing the right Python framework is a strategic choice, as the decision straightaway influences performance, security, scalability, time-to-market, and ROI. This blog offers a comparative analysis of the Python web frameworks, covering their pros, cons, and ideal use cases. Whether you are looking to hire Python developers or kickstart your next Python project, this dedicated comparative analysis will guide you to make an informed decision.

Django

Django is a mature, full-stack, and open-source Python framework designed to develop scalable, secure, and data-driven web applications. Created in 2003 by the web developers at the Lawrence Journal-World newspaper, the framework gained popularity for its “batteries-included” philosophy, which incorporates versatile, built-in tools that simplify and speed up the development process.

It follows a model-view-template (MVT) architecture, where each component has specific functions. Models represent the data, views manage the user interface, and controllers manage the application’s logic. The JetBrains Django Developers Survey 2023 revealed that 73% of developers used the framework for full-stack development, 61% for building APIs, and 4% for other purposes, indicating its widespread preference in web development projects.

Features

• ORM (Object-Relational Mapping)
  This salient feature of Django enables developers to define databases using Python code, rather than relying on SQL. It makes database interactions seamless and error-free by automatically handling queries.
• Admin Panel
  Django features a ready-to-use, auto-generated admin panel that allows developers to manage content, users, and data with minimal effort. It saves lots of development time and accelerates the project's speed, especially while working on content-heavy websites.
• Authentication and Authorization
  The framework features built-in user management systems that make it easier to manage user authentication, logins, and permissions. This ensures that only the right set of audience access to the right features.
• URL Routing
  Clean, regex-based URL routing helps developers understand how URLs map to views or functions, making page navigation and rendering organised.
• Security
  Built-in security features protect against threats like cross-site scripting (XSS), cross-site request forgery (CSRF), SQL injection, and clickjacking. These security best practices enable developers to build safe and secure web applications by default.
• Template Engine
  The template engine in Django enables developers to create dynamic web pages by combining HTML with Python data. This ensures cleaner code by separating the frontend presentation layer from the backend application logic.

Pros

• Rapid Development
  The batteries-included architecture and unique built-in features like ORM, admin panel, and authentication enable faster building, testing, and launching of complex applications compared to other frameworks.
• Scalability
  The flexible architecture and caching support make Django suitable for evolving, data-heavy platforms. It seamlessly supports and scales high-traffic platforms like Instagram and Pinterest.
• Community and Documentation
  Django has a record of 84.4k stars on GitHub, pointing to its large and active community with comprehensive documentation. This means developers have access to ample amounts of resources, libraries, and plugins, and can always find long-term maintenance support.
• Security 
  Offers secure-by-default protection against web vulnerabilities like CSRF, XSS, SQL injection, and clickjacking, and helps businesses to protect sensitive user data efficiently.

Cons

• Learning Curve
  Django has a steeper learning curve due to its rigid project structure and extensive feature sets. Hence, new developers may find it difficult compared to simpler micro-frameworks like FastAPI or Flask. 
• Overhead
  Django’s complex configurations and built-in tools can make it unsuited for small projects. Developers may find the framework slowing down the performance of lightweight, simple apps.

Use Cases

• Content Management Systems (CMS) 
  Django, with its modular structure and third-party packages like Django CMS and Wagtail, enables developers to build scalable and secure CMS platforms that allow businesses and organizations to develop, manage, and deliver content without requiring extensive coding skills. 
• E-commerce Platforms 
  Django’s robust and secure framework is ideal for powering e-commerce solutions that handle product catalogues, payment gateways, customer data, and inventory management. Its security features protect against common web threats, making it reliable for handling financial transactions, and the modular structure allows for seamless customization and integration with third-party tools to provide order tracking, shopping carts, and CRM. 
• Social Networks 
  Ideal for creating social networking platforms with its feature sets like user authentication, session handling, and real-time data management. It allows the creation of user profiles, news feeds, messaging systems, and data structures. Perfect for creating high-traffic environments, with Instagram being the prominent instance of a Django-powered app.
• Data‑Driven Applications
  Django’s powerful ORM, seamless integration with multiple databases (MySQL, NoSQL, and PostgreSQL), and compatibility with data analytics libraries enable the creation of data-intensive web apps, like analytics dashboards, real-time reporting systems, and machine learning integrations. The framework enables developers to easily query, filter, and manipulate data and present the information to the end user clearly and interactively. 
• Any Project Requiring Rapid Development 
  Django is perfectly suited for projects demanding fast time-to-market without compromising on code quality. Its batteries-included philosophy offers built-in features like admin dashboards, authentication, form handling, and URL routing, which allow developers to deliver MVPs by reducing development time. Hence, it is ideal for startups, prototyping, and agile software development.

Flask

Flask is Python’s micro-framework based on WSGI (Web Server Gateway Interface) and Jinja2 templates. It's a standard interface for backend web applications. Created by Armin Ronacher and launched in April 2010, Flask is minimal yet highly extensible compared to Django. The 2023 Python Developer Survey listed Flask as a dominant choice among Python developers, with a 33% Web framework usage share. 
While Django has a “batteries-included” approach offering complex functionalities, Flask has a much simpler and flexible core that provides routing, request handling, templating, session, and cookie support. It doesn't offer any database, ORM, or ODM, making it flexible for developers to choose the components they require for development. Netflix, Reddit, and Airbnb are some of the prominent websites using this Python framework.

We used the Flask web server to front our Python scripts. Our primary requirement was a REST API, and thus we had no interest in building a UI or having any use for databases; Flask worked perfectly for us. Flask is also utilized by multiple Python applications at Netflix, providing us with easy in-house support. We looked at Django and Pyramid as well, and eventually went with Flask — which offered us the most adaptability and ease of implementation.

— Netflix TechBlog

Features

• Routing
  Flask offers a simple decorator-based system to define URL routes. The @app.route(...) allows developers to map URLs with application logic. Flask also supports URL converters, dynamic URL components, and route grouping via Blueprints, enabling an intuitive and scalable project execution.  
• Request Handling
  It handles HTTP requests in a simple way, enabling developers to access request parameters, data, and headers with ease. It supports the GET, POST, PUT, DELETE, and PATCH methods, flawless file uploading, request hooks like before_request and after_request, and easy access to cookies, headers, and client IP, making the overall request processing both flexible and expressive.  
• Template Rendering
  The Jinja2 default template in Flask allows clean separation of the presentation layer from logic. Jinja2 supports macros, template inheritance, sandboxing, and filters. Also, extensions like Flask-Bootstrap further simplify template styling.  
  Armin Ronacher, the founder of Flask, talks about the framework’s versatility and how it was first used with HTML, then YAML for infrastructure, and now chat templates.
• Session Management
  The framework offers session management support to manage both user-specific and store-specific data. It stores session data in secure cookies (using the ItsDangerous library) by default on the user’s browser, which is protected with encryption to prevent tampering. Session management helps in the easy tracking of user preferences, login status, etc, without having to set up a full database system.  
• Extensions
  Even though the core is minimal, Flask features a rich ecosystem of libraries and extensions that can be used to enhance functionality. Flask‑SQLAlchemy offers ORM support, Flask‑WTForms or Flask‑Formalchemy for form validation, Flask‑Login for authentication, Flask‑Mail for email, Flask‑Uploads for file handling, and many more. These extensions integrate seamlessly without bloating the core framework.

Pros

• Simplicity
  Flask has a minimal setup, and beginners find it easy to learn and understand. It allows developers to seamlessly build apps without getting stuck with complex configurations or unnecessary tools. 
• Flexibility
  Flask offers developers the liberty to choose libraries, tools, and architectures to tailor customised or experimental projects as per their development needs. Unlike the full-stack frameworks, Flask doesn't impose any unnecessary rules or predefined structures. 
• Minimal Overhead
  Flask assures minimal overhead, since it only provides the essentials, making app development fast and lightweight. It allows efficient resource usage and lowers performance costs compared to large, pre-packaged frameworks.
• Community Support
  The framework features a strong community base and extensive documentation. This means developers can easily find tutorials, extensions, and necessary support for smoother development, which reduces the overall time spent troubleshooting. 

Cons

• Limited Built-in Features
  Flask is a minimal framework and offers only the essentials, meaning developers will need to rely on third-party libraries and extensions for accessing advanced features for processes like authentication, database handling, and form validation.
• Learning Curve for Complex Projects
  Flask offers optimal support for building small apps, but as the application grows complex, developers will require careful planning and structuring to ensure scalability and security. Hence, for complex projects, Flask is less compatible compared to full-stack frameworks.

Use Cases

• Small to Medium-Sized Web Applications
  Flask is ideal for building small to medium-sized web applications that demand quick deployment and light infrastructure. Its modularity and simplicity allow efficient handling of app development and maintenance.
• Prototyping and Proof of Concepts
  Since Flask is minimal and easy to set up, developers often use it to develop prototypes or proof-of-concept apps. This makes testing ideas and functionality much faster without a heavy upfront investment. 
• RESTful APIs
  Due to its flexible and minimal nature, Flask is widely used to build RESTful APIs. Its features, like routing, request handling, and data response management, make it a go-to framework for backend API development. 
• Microservices
  Flask’s minimal and lightweight design makes it an excellent choice for microservices architecture. Its modular design allows integration with other services without affecting its performance and manageability.
• Educational Projects
  Flask is easy to learn and demonstrates the core web development processes clearly, making it perfect for educational projects. Students can focus on understanding routing, templating, and HTML without being overwhelmed by complexity. 

FastAPI

FastAPI is a modern, high-performance, and asynchronous web framework based on Python. This micro-framework was created by Sebastián Ramírez and released in December 2018. It was primarily designed to simplify and accelerate the development of web APIs and backend services.

If anyone is looking to build a production Python API, I would highly recommend FastAPI. It is beautifully designed, simple to use, and highly scalable. It has become a key component in our API first development strategy and is driving many automations and services, such as our Virtual TAC Engineer.

— Deon Pillsbury, Senior Software Technical Leader, Cisco.

FastAPI is based on an ASGI server, “Uvicorn,” and a web micro-framework, “Starlette”. The framework seamlessly combines Python’s productivity and ease with the high performance of asynchronous programming to deliver scalable and fast web applications. Its ability to automatically generate interactive documentation through Swagger UI and ReDoc saves developers time while improving usability. With industry unicorns like Microsoft, Netflix, and Uber adopting the framework, it has gained widespread popularity. Overall, Fast API offers robust features that deliver dramatically better performance compared to Flask.

Features 

• Asynchronous Support
  FastAPI is built on Python’s native asyncio library; hence, it supports asynchronous programming that enables developers to handle multiple requests concurrently. This feature makes the framework ideal for high-traffic platforms, real-time applications, and microservice architectures, boosting their scalability and performance.
• Automatic API Documentation
  FastAPI uses tools like Swagger UI and ReDoc to automatically generate interactive API documentation based on Python type hints, code, and docstrings. This saves time, improves developer efficiency, and helps teams or clients understand how to test and interact with the APIs. 
• Type Hints for Data Validation
  FastAPI leverages Python’s type hints to provide automatic request validation and error handling. This improves code reliability, reduces bugs, and reduces the overall risk in production. 
• Fast Development
  FastAPI combines Python’s intuitive syntax and built-in features like dependency injection, validation, and documentation to facilitate faster development and deployment of robust APIs. 
• Built-in Security Features
  The built-in security features in FastAPI ensure protection against common security threats like XSS and SQL injection attacks, without requiring any third-party configurations.

Pros

• High Performance
  FastAPI’s asynchronous request handling capabilities improve performance. It significantly outperforms Flask and Django due to its ability to handle tens of thousands of requests per second. 
• Automatic Documentation
  Using Swagger UI and Redoc, FastAPI automatically generates interactive API documentation. This feature simplifies API testing and usage, saves development time, ensures consistency, and provides a clean, user-friendly interface for testing endpoints. 
• Type Safety
  The framework ensures strict data validation during runtime by leveraging Python type hints. This enhances code safety, reduces errors, improves developer productivity, and makes APIs more reliable by detecting mismatches well before they cause issues in development.
• Pythonic Syntax
  FastAPI follows Python’s clean and idiomatic syntax, making it familiar to Python developers. The syntax design possesses modern features like await/async, which make writing, reading, and maintaining code easy. 
• Growing Ecosystem
  FastAPI's community is expanding. Even though, not as mature as older frameworks, it has a rich ecosystem of extensions and libraries that is growing. Association with big names like Microsoft and Uber is backing the framework, making it more future-proof. The framework features 88k stars on GitHub, pointing to its emerging popularity. 

Cons

• Learning Curve
  FastAPI's features, like asynchronous programming, dependency injection, and type hinting, even though powerful, may require developers to experience a steeper learning curve, which can lengthen the development time.
• Maturity
  When compared to older frameworks like Django and Flask, FastAPI is relatively new and young. Meaning, its tools, plugins, and overall stability are still evolving, with constant changes and updates. 

Use cases

• API Development
  FastAPI is specifically suited for building robust APIs for a range of applications, including mobile apps, IoT devices, and web services. With its automatic documentation, async support, and type validation, it helps deliver reliable, secure, and scalable APIs with minimal effort and maximum performance.  
• Real-Time Applications
  Because of its asynchronous capabilities, FastAPI forms an ideal choice for building real-time applications such as live dashboards, chat systems, online streaming platforms, and IoT control systems.  
• Prototyping
  The simplicity and automatic documentation ability make it perfect for rapid prototyping. Developers can test ideas and validate business logic, all while composing clean and scalable code. 
• High-Concurrency Projects
  Projects requiring high concurrency levels, like trading systems, IoT platforms, SaaS applications, and online marketplaces, can benefit from FastAPI's async-first design, which ensures efficient resource usage and high performance. 
   

Choosing between Django vs. Flask, vs. FastAPI as the Python framework for your next project solely depends on your project’s complexity, team expertise, and goals. Django is best suited for complex, large-scale applications, while Flask’s simplicity and flexibility are ideal for small to medium-sized applications and microservices, and FastAPI stands as the go-to choice for high-performance, real-time applications requiring faster development cycles.

Now, which Python framework should you choose? The reality is, there is no single right answer. Each framework possesses its own strengths and trade-offs. The decision should be made based on your project’s complexity, performance goals, developer team expertise, and overall scalability requirements. Choose one that aligns most closely with your business goals and long-term vision.

WAC, being one of the best Python Development companies, empowers your business to harness the power of these Python frameworks and tailor solutions that align with your vision. Hire our vetted Python developers who ensure that your applications are secure, scalable, and future-proof, driving measurable business growth.