Flask-Bcrypt is a Flask extension that provides bcrypt hashing utilities for your application.

Due to the recent increased prevelance of powerful hardware, such as modern GPUs, hashes have become increasingly easy to crack. A proactive solution to this is to use a hash that was designed to be “de-optimized”. Bcrypt is such a hashing facility; unlike hashing algorithms such as MD5 and SHA1, which are optimized for speed, bcrypt is intentionally structured to be slow.

For sensitive data that must be protected, such as passwords, bcrypt is an advisable choice.


Install the extension with one of the following commands:

$ easy_install flask-bcrypt

or alternatively if you have pip installed:

$ pip install flask-bcrypt


You need Python Development Headers to install py-bcrypt package, needed as a dependency. If you are on Mac OS or Windows, you probably have it already installed. Otherwise look for python-dev package for Debian-based distributives and for python-devel package for RedHat-based.


To use the extension simply import the class wrapper and pass the Flask app object back to here. Do so like this:

from flask import Flask
from flask.ext.bcrypt import Bcrypt

app = Flask(__name__)
bcrypt = Bcrypt(app)

Two primary hashing methods are now exposed by way of the bcrypt object. Use them like so:

pw_hash = bcrypt.generate_password_hash('hunter2')
bcrypt.check_password_hash(pw_hash, 'hunter2') # returns True