because sometimes a pocket knife is not enough

Flask is a microframework for Python based on Werkzeug, Jinja 2 and good intentions. And before you ask: It's BSD licensed!

Latest Version: 0.12.2

Flask is Fun

from flask import Flask
app = Flask(__name__)

def hello():
    return "Hello World!"

And Easy to Setup

$ pip install Flask
$ FLASK_APP=hello.py flask run
 * Running on http://localhost:5000/


What’s in the Box?

What do Flask Apps look like?

If you are looking for some example code of applications written with Flask, have a look at the sources of the examples on github:


Found a bug? Have a good idea for improving Flask? Head over to Flask's github page and create a new ticket or fork. If you just want to chat with fellow developers, visit the IRC channel or join the mailinglist. You can also directly add issues and feature requests to the issue tracker. Fork me on GitHub