Zxcvbn password strength estimator
Zxcvbn for Vaadin integrates the zxcvbn password strength estimator into Vaadin. The estimator analyzes the password based on various dictionaries and patterns to find the easiest way a hacker might guess the password.
This add-on provides a ZxcvbnIndicator component that can be connected to a TextField to show a visual representation of the password strength as the user types into the field. The password strength rating (0 - 4) is also sent to the server once the user has finished typing.