Django vs. FastAPI - a detailed comparison

Introduction

The previous article analyzed the differences between DRF (Django Rest Framework) and FastAPI. This article will focus on FastAPI but compare it with Django. It will be similar to the previous article since DRF is built on Django, but there will be some differences.

And as usual, remember that at Sunscrapers, we are always happy to help you with the decision and further development in any Python-related framework, as we have specialized in Python development for quite some time.

What is Django

First, let's take a quick look at what Django is. Most of you will know the answer to this question, but to maintain professionalism, let’s briefly describe it.

Django is a web framework written in Python. It follows the model-template-view architectural pattern and a DRY principle (Don't Repeat Yourself). It's naturally open-source, so it can be used for any project. Django was founded in 2005 and is well maintained by independent non-profit organizations.

What is FastAPI

FastAPI is a micro-web-framework - so it’s much more lightweight than Django. As a result, it’s great for creating fast APIs (especially for serverless applications). FastAPI is based on Pydantic and types hints to validate, serialize, and deserialize data. It supports asynchronous programming and can run with Gunicorn and ASGI servers for production.

Main benefits of Django

Let’s take a look at the main benefits of using Django.

1. Security

Django has an excellent security feature built-in to avoid common attacks like CSRF, SQL injection, etc. In this aspect, Django is way better than FastAPI.

2. Authentification

Django creators have implemented excellent account management and authentication features.

3. Scalability

Django is a vast framework that allows you to scale the application quickly once your requirements grow.

4. Versatility

For the same reason, the framework is very versatile. However, we must remember that it can also be a drawback at some point.

5. Community

As Django has been on the market for some time now, the community built around it is vast, allowing users to ask questions and find solutions to problems quickly.

6. MVT Model

Django uses the MVT model - Model View Template. The Model is the backend part of the system that communicates with databases. View fetches data from the Model and maintains HTTP-related actions. The template is the representation part, which combines HTML with data gathered from the Model.

7. Build in database support

Django comes with a built-in ORM (Object-relational mapping) framework for developers to start using out of the box.

8. WebForms

Django has built-in ModelForms, which provides complete support for web forms, including input validation, CSRF, XSS, and SQL injection.

Main benefits of Fast API

Now let's take a look at what FastAPI has to offer.

1. Performance

FastAPI is way faster than Django and is one of the fastest web frameworks for Python. The only faster frameworks are Starlette and Uvicorn (fun fact - FastAPI is built on Uvicorn).

2. Concurrency

It used to be challenging, but since Python 3.4 Async I/O was added, FastAPI allows out-of-the-box concurrency. As a result, you will also avoid creating event loops or async/await management. As you may imagine, this will eventually impact the efficiency of your application.

3. Documentation support

FastAPI generates excellent documentation that is easy to read and use by frontend engineers and simplifies API endpoints' testing. The documentation is browser-based, and it's based on Swagger or ReDoc GUI.

4. Dependency injection

FastAPI comes with a built-in dependency injection solution. It ensures that classes are not directly dependent on each other. Thanks to that, the changes in the code are easier to make. The modularity of the code is also increased, making it easy to scale. The path operation function allows engineers to declare relevant dependencies.

5. Seamless central exception handling

To do exception handling, you just need to use @app.exception_handler annotation or app.add_exception_handler function to register the response for an Exception, which will be managed automatically by FastAPI.

6. Validation of data

Last but not least is the validation of data. It detects wrong data types and returns proper exceptions in JSON. Again, it uses the Pydantic module to simplify the process, making the code less prone to errors.

Drawbacks of Django

Let's now see both frameworks' drawbacks - we will start with the Django web framework.

1. NoSQL Databases

Django does not have native no-sql database support. You can naturally use some external solutions, but they don't all cooperate easily with ORM.

2. REST support

Django does not have out-of-the-box REST support. Therefore, if you want to create a REST Api easily, you need to use the DRF (Django Rest Framework) we described before.

3. Performance

Django has worse performance than FastAPI - primarily because of the framework size - we need to remember that FastAPI is a MICRO Framework.

4. Learning curve

Again, because of its size - the learning curve is much steeper than the one of FastAPI.

5. Lack of interactive documentation

While Django is pretty well documented, it lacks interactive documentation like FastAPI does.

Drawbacks of FastAPI

The last thing we need to look at is the drawbacks of FastAPI. There are only a few, but it's still important to look at them for a complete understanding.

1. Security

There is no built-in security system. Instead, you have to use fastapi.security module to manage it.

2. Small community

FastAPI is relatively new (compared to Django), so the community and amount of materials are a bit smaller. But this will undoubtedly change over time, so it's not a huge issue.

Final remarks

So which should you choose?

It's clear that comparing FastAPI with Django is like comparing a bicycle with a car. Django is great, but if we want to create an API backend, there is a limited sense in using Django. So FastAPI will be a much better choice. On the other hand, if you are making a full-blown application, then Django will be a much better choice, especially since you can use Django Rest Framework to handle the API part of the system.

Of course, the final choice is always challenging. Hence we strongly recommend consulting professionals like us so that we can make a detailed analysis based on your business needs and requirements to see which option would be better.