Flask is a lightweight and open-source Python framework used for building web applications. It’s known as a microframework because it provides only the essential tools you need—like routing, request handling, and template rendering—without forcing a fixed project structure or adding a lot of built-in features. This gives developers the freedom to choose and add only the extensions they need, making Flask a good fit for both small projects and large, more complex applications. Since it focuses on core functionality, there’s no unnecessary overhead, and you can easily extend it with tools and libraries whenever required.
Flask also includes a built-in WSGI server, which makes it convenient to run and test your application locally during development. This local server allows you to view your web pages right on your system while you’re working. Additionally, Flask provides an interactive debugger that helps you quickly identify and fix errors, making the development process smoother and faster.
It has Built-in support for GET, POST, PUT, and DELETE methods and can also handle form submissions, JSON data, and file uploads. At the database level, it works with MySQL, PostgreSQL, SQLite, MongoDB, etc., through extensions.
Simple way to map URLs to Python functions.
@app.route("/hello")
def hello():
return "Hello, Flask!"When building a web application, the last thing you want is a framework that feels heavy or restrictive. Flask avoids this problem by offering a clean, simple foundation that developers love.
Flask, a lightweight Python microframework, has become popular for exactly these reasons. Unlike heavy frameworks that come with many built-in features you may never use, Flask provides only the basics—routing, request and response handling, and easy integration with Jinja2 for templating.
This minimal setup doesn’t limit you; it actually gives you the freedom to add only the tools you need. You can include extensions such as Flask-SQLAlchemy for databases, Flask-WTF for forms, Flask-Login for authentication, or Flask-Migrate for database migrations.
In detail, Flask-SQLAlchemy simplifies the way you work with databases by allowing you to use Python code to create tables, store data, and run queries, instead of writing long SQL statements manually. Flask-WTF makes working with forms effortless by handling validation, protecting forms from security issues, and reducing the amount of repetitive code you need to write. Flask-Login takes care of user authentication by managing login sessions, remembering logged-in users, and restricting certain pages so that only authorized users can access them. Flask-Migrate helps you smoothly update your database structure whenever your models change, ensuring that your database stays consistent without losing any existing data. Together, these extensions give Flask the power and flexibility to handle real-world applications while keeping the development process clean, efficient, and beginner-friendly.
Flask is easy for beginners to pick up, and its built-in development server and debugger help speed up testing and development. You can quickly start building APIs, dashboards, websites, or small utilities with just a few lines of code and extend the project as it grows. Working with routes in Flask is simple—you just connect a URL to a Python function using the @app.route() decorator. Jinja2 templates also make it straightforward to display dynamic data in HTML without repeating code. Flask handles JSON smoothly and supports different HTTP methods, which makes it a solid choice for creating REST APIs.
One of Flask’s biggest strengths is how flexible it is. It works well with almost any database, supports modern front-end frameworks like React and Vue, and can run on a small device like a Raspberry Pi or on large cloud servers. It also has a helpful community and clear documentation, which makes it beginner-friendly while still giving experienced developers the control they want. In a world where developers look for efficient and scalable solutions, Flask proves that a lightweight framework can still handle a wide range of real-world needs.
To read more about What is Flask Python & It's Key Features, refer to our blog What is Flask Python & It's Key Features.