Having a strong password is an essential thing in making accounts more secure. The following scripts can help your users to open an account with a powerful password in order to prevent malicious attacks.

Password Strength Meter is a JQuery plugin that uses a smart algorithm to determine the password strength. For instance, if the password matches the username it will be “bad”; if it is less then 4 characters is is “too short”; if it is long and contains letter, numbers and non-alphanumeric characters it is a “strong” password.

Ajax Password Strength Meter Script is a small JQuery Plugin that provides an easy way to show the strength of a user’s password. Some of the things can be adjusted inside this script such as: messages, length/height of the bar.

How to Make a Password Strength Meter Like Google is a tutorial from Code and Coffee. The author chosen to base the code off of the kind folks over at Intelligent Web.

There theory is to calculate how many different combinations there are for the password you enter, then determine how many days it would take to crack your password. The algorithm returns a percentage that we then in turn convert to a nice GUI for the end user to see.

Password Strength Checker

How to make a password strength meter for your register form

Ext.ux.PasswordMeter Extension Class is an application developed by Eelco Wiersma, that uses an algorithm based on code of Tane and Steve Moitozo.