FastAPI vs Flask: A quick comparison

Blog
23 September 2022
Complete Guide for CTO & IT Directors
Microservices under X-Ray Three books image Download free ebook

There are many web development frameworks available for Python. Two of the most popular web development frameworks are FastAPI and Flask. In this article, we will compare and contrast these two web development frameworks. However, we need to make a small FastAPI vs Flask distinction.

Micro web vs web

A web framework is a collection of packages or modules which allow you to write web applications or services. A micro web framework is a framework which is designed to be as small as possible, providing only the most essential features.

Some popular web frameworks include FastAPI, Django, Ruby on Rails, and Express.js. Some popular micro web frameworks include Flask and Sinatra. Today, we will focus on Flask – a micro web framework written in Python and FastAPI – a batteries-included framework for web.

What is FastAPI?

FastAPI Python framework

FastAPI is a modern framework for creating Python APIs using standard Python type hints. 

It is a batteries-included framework that comes with all the necessary features and tools you need to create a production-ready API. FastAPI is heavily inspired by and borrows a lot from the excellent work done by the developers of the Flask framework.

Like Flask, FastAPI is lightweight, modular, and easy to use. It is also very fast, as its name implies. FastAPI is the fastest framework for building APIs with Python, according to some benchmarks.

What is the FastAPI framework good for?

Highly scalable

Another advantage of FastAPI is that it is highly scalable and can be used to build large-scale applications. This is because FastAPI uses the asynchronous programming paradigm. Asynchronous programming is a type of parallel programming in which a program can perform multiple tasks simultaneously. This allows FastAPI to process multiple requests at the same time. As a result, FastAPI can handle a large number of requests without any performance issues. 

Highly customizable

FastAPI is highly customizable and can be used to build applications with custom requirements. This is because FastAPI is built on top of Starlette and Pydantic. Starlette is a lightweight ASGI  (Asynchronous Server Gateway Interface) framework that is used to build high-performance web services. Pydantic is a data validation library that is used to validate and convert user-provided data into Python objects. This allows FastAPI to be highly customizable. In addition, FastAPI comes with a number of built-in features that can be used to build applications with custom requirements.

Built-in features

FastAPI comes with a number of built-in features that can be used to build applications with custom requirements. One of the built-in features of FastAPI is OpenAPI support. FastAPI supports OpenAPI, which is a specification for building APIs. OpenAPI is a popular specification for building APIs. It is used by a number of companies, including Google, Microsoft, and Amazon. OpenAPI allows developers to build APIs that are easy to use and understand. In addition, OpenAPI allows developers to generate documentation for their APIs. This makes it easy for other developers to use and understand the APIs.

Data validation

FastAPI comes with data validation support. This allows developers to validate the data before it is processed by the API. Data validation is an important feature of any API. It allows developers to ensure that the data is valid before it is processed by the API. As a result, it prevents any invalid data from being processed by the API.

What is the FastAPI framework bad for?

It’s new

FastAPI is a new project and is still in active development. While this means there are plenty of features and improvements still to come. Because FastAPI is new, it’s not as widely adopted as some older frameworks. This could make it more difficult to find support and resources if you run into problems. 

What is Flask?

Flask Python framework

Python is used to create the Flask web application framework. It is designed to be straightforward to use and simple to scale up. Because it doesn’t require any specific tools or libraries, Flask is referred to as a microframework.

Flask is a project of the Pallets team, which also maintains Werkzeug, Jinja, MarkupSafe, Click, and several other Python libraries. Flask was created in 2010 by Armin Ronacher and is released under the BSD license.

What is the Flask framework good for?

Flexible

Flask is very flexible. It gives developers a lot of control over how they want their web applications to look and behave. This is due to the fact that Flask is based on Werkzeug, a WSGI (Web Server Gateway Interface) toolkit, and Jinja2, a templating engine. Werkzeug and Jinja2 give developers all the power they need to create custom applications.

Small-scale projects

Flask is a good choice for small to medium-sized projects that don’t require a lot of bells and whistles. It’s intended to be used alongside your existing webframework and application server (or as a standalone server). It’s lightweight, fast, and simple, which makes it perfect for small applications.

Ease of use

If you’re looking for a framework that’s simple to learn and use, the Flask framework is a good option. It has a huge community and the Flask documentation is good and up-to-date.

Community

Flask has a large and supportive community, which makes it easy to find help and support when needed. The code is open source, so the community can contribute to Flask by reviewing and improving the code. Flask is built on Python, which means you can use your existing Python skills to get up and running quickly. Python is easy to learn and is used by many companies for their web applications, so you have a good base to build on.

What is the Flask framework bad for?

Lack of data validation

Flask does not have built-in data validation. This means that you will have to validate your data manually or use third-party modules, such as Flask-Marshmallow or Flask-inputs.

Flask’s slow nature 

In general, Flask’s slow nature is a drawback. As a microframework, Flask does not offer the same level of features and functionality as a full-stack framework.

  • Flask doesn’t include some of the features that other frameworks have. This can make development slower because you have to add these features yourself.
  • Flask is based on Werkzeug, which is a WSGI (Web Server Gateway Interface) toolkit. This makes it slower than some other frameworks.
  • Flask doesn’t have a built-in template engine. This means that you have to choose and install a template engine yourself, which can add to the development time.

No support for asynchronous code  

While Flask does support async, it doesn’t have built-in async support like some of the other competing frameworks. This means you’ll need to use third-party modules if you want to use async.

Comparing Flask and FastAPI

Performance

When it comes to performance, FastAPI is the clear winner. It is built on top of Starlette, which is a high-performance ASGI framework. Flask, on the other hand, is a traditional webframework and is not designed for performance. It is built on top of the Werkzeug WSGI (Web Server Gateway Interface) toolkit and Jinja2 templating engine.

Features

FastAPI includes many features that are not available in Flask. These features include:

  • automatic validation
  • automatic documentation
  • support for asynchronous requests
  • built-in test client
  • built-in profiler
  • SQLAlchemy integration

Flask, on the other hand, includes a few features that are not available in FastAPI. These features include:

  • support for WSGI middleware
  • Jinja2 templating engine
  • integrated development server
  • unit testing support

Automatic documentation

Swagger automatic documentation

The FastAPI framework can generate the OpenAPI specification for all the API endpoints in your code base. The OpenAPI specification is a YAML/JSON format for describing APIs. It is used by many large companies, including Google, Microsoft, and IBM, as a way to standardize how APIs are described. The specification is maintained by the OpenAPI Initiative, which is a consortium of companies and individuals that are committed to standardizing how APIs are described.

The documentation generator uses a friendly user interface, Swagger-UI for automated, generated documents. Swagger-UI uses a web interface for the REST API documentation.

Flask, on the other hand, has no built-in feature for automated, generated docs. So, you will have to install Swagger-UI or any other tool for documenting API endpoints and find a way to document all the endpoints automatically. Feel free to explore Flasgger if you would like to automatically generate the REST API documentation.

Flask and FastAPI for data science

Data science is a branch of computer science that deals with the extraction of knowledge from data. It is a relatively new field that combines elements of statistics, computer science, and mathematics.

Data scientists use a variety of techniques to extract knowledge from data, including machine learning, statistical modeling, and data mining. They use this knowledge to build machine learning models that can be used to make decisions or predictions.

In data science, engineers may not restrict themselves to building only an ML model but also they may need to present their solution to a client so that they can extend their machine learning model based on new data received from the untested grounds.

One way to test the ML model is to expose it to real-world data. You can achieve that by building web apps for the general public and leveraging the data gathered by the users for model building or improving your existing solution. In the data science world, it is a common practice to use this method for expanding models.

Hence your solution will work when you deploy it to the cloud. For this, you’ll need some web frameworks. Flask and FastAPI are great options to do so. Remember that Flask is better suited for minimalistic web applications while FastAPI is better for high-load enterprise software.

Flask and FastAPI conclusion

Flask is a WSGI web application framework that is small and lightweight. It is intended to be simple to use and easy to scale up to complex applications. FastAPI is a modern framework for creating Python APIs based on standard Python type hints.

Both are easy to use and great for building web apps and APIs. Flask is more established and has a larger community, while FastAPI is newer and has better performance.

If you’re just starting out, Flask is a great choice. If you’re looking for better performance, FastAPI is a great option.

Latest Posts
now next later roadmap

Navigate Easily: A Step-by-Step Guide to the Now Next Later Roadmap

Let’s be honest – strategic planning is essential for successful product management. The Now-Next-Later roadmap is a powerful tool that helps teams prioritize tasks, streamline efforts, and align stakeholders. This guide delves into the intricacies of this roadmap, providing a comprehensive overview of its benefits and implementation. But first, let’s get some basics down for […]

/

Scrum: How to Work Together

With the popularity of the scrum framework among software development teams, it’s growingly important to learn how a scrum team works to meet its goals. Scrum Process Overview Scrum is an agile project management framework widely used in IT but can be applied to other fields as well. The framework facilitates the management of complex […]

/
event storming

Event Storming: How to Boost Your Software Development Process with a Simple Technique?

Event storming is a dynamic workshop technique that supports domain-driven design in software development. It can boost the team’s efficiency and reduce error risk, minimizing the back-and-forth in the development lifecycle. If you haven’t been living under a rock, you’re probably familiar with the concept of brainstorming. It’s a widely used term for the process […]

/
rails vs sinatra

Rails vs Sinatra

In the rapidly evolving world of software development, web frameworks have become essential tools for building robust and scalable web applications. These frameworks provide a structured environment that streamlines the development process, offering pre-written code, libraries, and guidelines that help developers avoid repetitive coding tasks, thus significantly enhancing productivity and ensuring best practices. Within the […]

/
android webstockets

Introduction to Android WebSocket

WebSockets have become a pivotal technology in enabling real-time communication for Android apps, offering a dynamic way to send and receive messages instantaneously. This technology facilitates a persistent connection between the client (Android app) and the server, bypassing the traditional HTTP request-response model to allow continuous data flow through a single TCP connection. The WebSocket […]

/
smart contracts audit

Introduction to Smart Contract Audits

In the blockchain world, smart contracts are key to decentralized applications (dApps), automating transactions and enforcing agreements without intermediaries. These contracts handle significant digital assets and perform crucial operations, making their security paramount. Smart contract audits are thus essential, scrutinizing the contract’s code for vulnerabilities to prevent potential security breaches. These audits are crucial for […]

/
Related posts
django apps

Django Apps, Projects, and Other Caveats

Django, emerging as a significant player in the realm of web frameworks, stands out as a Python-based toolset that revolutionizes the way developers approach web application development. It is not merely a framework but a holistic environment that encapsulates a developer’s needs for building robust, efficient, and scalable web applications. Born out of a practical […]

/
bots with python

Bots with Python 101

As we continue to embrace the digital age, we encounter countless innovative solutions that improve our daily lives, making mundane tasks more efficient, or even automating them entirely. One such innovative solution is the ‘bot’, a broad term that has various definitions depending on the context in which it is used. In its essence, a […]

/
python vs scala

Scala vs Python: What’s Better for Big Data?

In the world of big data processing and analytics, choosing the right programming language is crucial for efficient data management and effective decision-making. Python and Scala are two popular programming languages used in data science projects and processing, each with its unique strengths and features. This article will explore the key differences between Python and […]

/
dependency injection python

Dependency Injection in Python Programming

Dependency Injection (DI) is a design pattern used in software development to reduce coupling between components and improve code maintainability, testability, and scalability. In this blog post, we will explore the concept of Dependency Injection, its advantages in Python, how to implement it, and best practices for using it effectively. What is Dependency Injection (DI)? […]

/
django hosting

Hosting for Django? Here’s what you need to know.

Django is a robust web framework for Python that enables programmers to swiftly build web apps. But once you’ve built your application, the next step is to get it online and available to the world. That’s where hosting comes in. In this article, we will explore the various options available for hosting Django applications. Types […]

/

Python Web Application Examples. Top 7 Cases

Python lies at the heart of many leading web applications. Businesses and programmers love this language for its simplicity which, paradoxically, facilitates the development of very complex systems. Find out how top big tech companies use Python in their platforms. Python is the language of choice for data scientists, machine learning experts, and backend developers. […]

/
Talk with experts

We look forward to hearing from you to start expanding your business together.

Email icon [email protected] Phone icon +1 (888) 413 3806