ASP.NET Password Strength Regular Expression

ASP.NET Password Strength Regular Expression. Customize n numbers of upper case, digits, Special characters. Shown below is the regular expression for password strength with n number of digits, Upper case, special characters and at least 12 characters in length. (?=^.{12,25}$)(?=(?:.*?\d){2})(?=.*[a-z])(?=(?:.*?[A-Z]){2})(?=(?:.*?[!@#$%*()_ +^&}{:;?.]){1})(?!.*\s)[0-9a-zA-Z!@#$%*()_+^&]*$ Explanation: (?=^.{12,25}$) -- password length range from 12 to 25, the numbers are adjustable (?=(?:.*?[!@#$%*()_+^&}{:;?.]){1}) -- at least 1 special characters (!@#$%*()_+^&}{:;?.}) , the number is adjustable (?=(?:.*?\d){2}) -- at least 2 digits, the number is adjustable (?=.*[a-z]) -- characters a-z (?=(?:.*?[A-Z]){2}) -- at least 2 upper case characters, the number is adjustable