Simplistic strength estimation gives bad advice. Without checking for common patterns, the practice of encouraging numbers and symbols means encouraging passwords that might only be slightly harder for a computer to crack, and yet frustratingly harder for a human to remember.
zxcvbn, named after a crappy password, is a JavaScript password strength estimation library. Use it to implement a custom strength bar on a signup form near you!
correct horse battery staple 😉
zxcvbn: realistic password strength estimation →
zxcvbn demo →