What is Flask?

Flask is a simple toolkit that lets coders make websites and apps using Python. It gives just the basics so you can add what you need without extra weight.

7 min read min de lecture

~$ man flask

What is Flask?

Web Dev & SaaS gneurone encyclopedia
Flask is a simple toolkit that lets coders make websites and apps using Python. It gives just the basics so you can add what you need without extra weight.

definition

Flask is a micro web framework for Python that provides the core tools needed to create web applications and REST APIs.

It was created by Armin Ronacher and relies on the Werkzeug WSGI library plus the Jinja2 templating engine while leaving database and other choices open to the developer.

Because it stays minimal, Flask is often chosen for small projects, prototypes, and services that need to stay lightweight and customizable.

Flask works like a basic set of Lego bricks: you get the pieces to build a simple structure quickly, then add your own extra bricks for color or features instead of getting a full pre-built kit.

key takeaways

  • Flask stays small on purpose so developers control every added component.
  • It handles URL routing, request handling, and HTML templates out of the box.
  • Extensions exist for login, databases, and testing when projects grow.
  • Flask runs on any Python version that supports its dependencies and stays fully open source.
  • Many teams use it to expose data through APIs that mobile apps or front-end code can call.

the 2026 job market

In 2026 demand stays steady for Python developers who can ship fast APIs and internal tools; startups and data teams continue hiring Flask skills for backend roles alongside FastAPI and Django positions.

Python Backend Developer · US $95k-$135k / Canada $85k-$120k CAD / UK £50k-£75kWeb Application Engineer · US $90k-$130k / Canada $80k-$115k CAD / UK £48k-£72k

frequently asked questions

How do you install Flask on a new project?

Open a terminal and run pip install flask inside a virtual environment. This adds the package and its dependencies so you can import it in your Python files right away.

Is Flask suitable for large production websites?

Yes, many companies run Flask at scale when paired with proper extensions, caching, and a WSGI server like Gunicorn. The framework itself stays small while the surrounding stack handles growth.

What is the difference between Flask and Django?

Flask gives minimal tools and lets you pick your own database and libraries, while Django includes an admin panel, ORM, and many built-in features by default. Choose Flask when you want more control and less boilerplate.

Can beginners learn Flask without prior web experience?

Yes, the official tutorial starts from a single file and adds features step by step. Basic Python knowledge is enough to follow along and build a working app in a weekend.

courses to go further

Python Flask Microservices
24 lessonsPython Flask MicroservicesComing soon
$ cat ./full-guide.mdPython Flask Microservices en pratique : le code et les commandes qui comptent vraimentread the guide →

related terms

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Auteur(s)

R

REHOUMA Haythem

Haythem Rehouma est un ingénieur et architecte IA et cloud, formateur et enseignant technique, avec un profil orienté IA médicale, AWS, MLOps, LLM/RAG et vision par ordinateur.