I like this entropy based password strength checker: https://github.com/dropbox/zxcvbn https://github.com/dropbox/zxcvbn Here you can see that it realizes tha

I like this entropy based password strength checker: https://github.com/dropbox/zxcvbn https://github.com/dropbox/zxcvbn Here you can see that it realizes that all your passwords are weak: https://lowe.github.io/tryzxcvbn/ https://lowe.github.io/tryzxcvbn/ (it says: cracked in minutes, or seconds, in an offline attack) And it does this without requiring uppercase or symbols or numbers. It even understands that passwords like "qwerty" are trivially cracked – it looks at how far the keyboard keys are from each other. Among lots of other things.