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. The add-on also contains a pure GWT version of the widget as well as low-level classes for interacting with the zxcvbn javascript library.