FastAPI vs Flask

FastAPI vs Flask | Popularity, Salary, Performance, Features, and Applications

Flask and FastAPI are popular Python technologies for building full-stack web applications and APIs. They are also popularly used for building backends for mobile, desktops, and other applications.

If you are already familiar with the Python programming language, you will find it easy to work with Flask and FastAPI.

FastAPI is a modern, fast (high-performance), web framework for building APIs with Python based on Pydantic, Starlette, and the standard Python type hints.

Flask on the other hand is an extensible micro web framework written in Python. Flask supports extensions that can add application features as if they were implemented in Flask itself.

Choosing which web framework to learn can be tricky, there are many factors to consider when learning a new technology or backend framework.

Popularity, opportunities, types of projects, salaries, resources, learning curve, etc. are some of the factors that many people consider when choosing to learn a new technology or a framework.

Here are some of the considerations you should make when choosing to learn a new backend framework.


If you want to learn a technology or framework solely for its popularity among developers, you should learn Flask.

Generally, Flask is more popular than FastAPI. According to a Stack Overflow survey of 2022, Flask is the second most commonly used Python Web framework by both professionals and those learning to code. It is used by 14.64% of developers.

On the other hand, FastAPI is the 3rd most commonly used Python web framework, it is used by 6.02% of developers according to the same survey.

But FastAPI is glowing quickly and getting a lot of traction among developers. It is worth noting that FastAPI is more loved by many developers than Flask.

As of 2022, FastAPI is loved by 67.74% of developers versus 32.26% of developers who dreaded it. On the other hand, Flask is loved by 48.41% of developers versus 51.59% of developers who dreaded it.

Ultimately, if your choice of which web framework to learn depends on popularity, you should learn Flask.

Plus, there are more opportunities for Flask Developers than for FastAPI developers because Flask is used by many companies that FastAPI.

However, because Flask is very popular and commonly used by many companies, there is going to be more competition for Flask opportunities than for FastAPI opportunities.

In this regard, a FastAPI developer may get a job easily because of less competition.


Another popular criterion that many people use as an incentive to learn a new web framework is salary. Salaries for developers differ from one company to the other and from one country to the other.

Experience is another factor that comes into play as far as salaries are concerned. The more experience you have with a certain technology or web framework, the more likely you are of getting a higher salary.

Generally, FastAPI developers get slightly higher salaries than Flask developers. A Stack Overflow survey reported that FastAPI developers get an average salary of $69,345 per year while Flask developers get an average of $67,105 per year.

Salaries Fastapi vs flask

So, if the salary is your major incentive for learning a language or web framework, you should learn FastAPI over Flask because you are more likely to get a higher salary as a FastAPI developer than as a Flask developer.

Also read Can Flask be used for Mobile app Development


Some web frameworks can be learned more easily than others. If you want a web framework that is beginner-friendly and very easy to work with, you should learn FastAPI.

FastAPI is very easy to work with even for complete beginners, you will be able to achieve a lot of functionality with just a few lines of code.

It has also been reported that FastAPI can help to increase the speed to develop features by about 200% to 300% and can reduce about 40% of human-induced errors. (FastAPI internal testing).

Flask is easy to work with as well, its syntax is easy to read and write. It is worth noting that Flask is a micro web framework and it does not come with a lot of features.

As a result, you will need third-party libraries to extend its functionality.

The good news is that there are many helpful resources for both Flask and FastAPI to help you learn the frameworks.

The Python (FastAPI and Flask) community is very big, active, and helpful, in case you get stuck with something.


Flask is classified as a microframework because it does not require particular tools or libraries. 

Flask has no database abstraction layer, form validation, or any other components where pre-existing third-party libraries provide common functions.

You will need Flask extensions to extend the functionality of your application.

Flask is used by many companies such as Pinterest, LinkedIn, CRED, Netflix, Reddit, Lyft, Trivago, Airbnb, MIT, Mozilla, Uber, and many others.

On the other hand, FastAPI is a fast (high-performance) web framework, it is generally regarded as faster than many Python-based web frameworks, thanks to Starlette and Pydantic.

FastAPI is fully compatible with (and based on) Starlette and Pydantic. So, any additional Starlette and Pydantic code that you have, will also work. FastAPI also supports asynchronous programming.

FastAPI is used by many companies such as Microsoft, Netflix, Uber, Cisco, Explosion AI, Hug, and many others.


Once you have evaluated all the factors, you can choose which web framework to learn depending on the factors that are on your side and what you want to build.

If you want a popular, extensible web framework that is easy to learn, you should learn Flask.

If you want a high-performance web framework that is beginner-friendly and can potentially fetch you a higher salary, you should learn FastAPI.