Code and Coffee has put together a password strength meter using Ajax to check the strength of a given password in real-time. Google and other web services are picking up on the trend of using these meters to inform new users, just how strong their chosen password is.
Using Code And Coffee’s demo page, I typed in the password, ( password ) and the meter read, VERY SECURE. Obviously, the algorithm needs some work, but the good news is, you can actually change the way the algorithm works. Code and Coffee decided to base their password algorithm off of Intelligent Web. Their algorithm calculates how many different combinations there are for a password, as it’s being entered, then determines how many days it would take to crack the password. The algorithm returns a percentage that is turned into a GUI for end users to see.
Code and Coffee has released the javascript file along with the demo.html page that you would need, in order to add one of these password meters to your site or service. There is also a detailed explanation as to how the code works which can be read, by clicking here.
Thoughts and Insanity From Jeff 
I found another two password strength checkers. Their algorithm based on words dictionary. Try one at microsoft.com and one at itsimpl.com. Please, try it, and write your thoughts. Good Luck! Jetman
I found a very simple one, it does not use dictionary but is enough for me http://www.codeassembly.com/How-to-make-a-password-strength-meter-for-your-register-form/
Hi,
You are not using AJAX anywhere in the demo. This is plain Javascript. AJAX seems to have been confused with Javascript & DHTML. To qualify as an AJAX solution you must post the password to the server and the passwd strength algorithm must execute on the server just as Google does it.