On the security side, Enzoic states that your "Password will be sent securely to our server to check if it's compromised," and it doesn't store your passwords.

Just type in a password, and it will compare it against a database of over 306 million passwords, collected over several years, in order to determine how unique it is.

If you tend to reuse passwords or haven’t changed one in years, you should assume your credentials are vulnerable and take steps to protect yourself.