JavaScript

JavaScript

ZIP code regex
ZIP code
XML regex
XML
UUID regex
UUID
URL regex
URL
Street address regex
Street address
SSN regex
SSN
Phone number regex
Phone number
Password regex
Password
Numbers only regex (digits only)
Numbers only (digits only)
Regex match words
Words match
Mac address regex
Mac address
IP address regex
IP address
HTML regex (regex remove html tags)
HTML
GUID regex
GUID
Email regex
Email
Date regex
Date
Password regex

Password regex

Password regular expression can be used to verify that a password provided is strong enough to provide better protection against bot brute force attacks. This method, however, does not guarantee that a password will have enough entropy to be completely safe.

JavaScript
JavaScript
Python
Python
Java
Java
C#
C#
PHP
PHP

Strong password regex

The regular expression below cheks that a password:

  • Has minimum 8 characters in length. Adjust it by modifying {8,}
  • At least one uppercase English letter. You can remove this condition by removing (?=.*?[A-Z])
  • At least one lowercase English letter.  You can remove this condition by removing (?=.*?[a-z])
  • At least one digit. You can remove this condition by removing (?=.*?[0-9])
  • At least one special character,  You can remove this condition by removing (?=.*?[#?!@$%^&*-])
/^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9])(?=.*?[#?!@$%^&*-]).{8,}$/

Test it!
/^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9])(?=.*?[#?!@$%^&*-]).{8,}$/

True

False

Enter a text in the input above to see the result

Example code in Javascript:

var passwordRegex = /^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9])(?=.*?[#?!@$%^&*-]).{8,}$/;
// Validate password
passwordRegex.test('secret'); // Returns false
passwordRegex.test('-Secr3t.'); // Returns true

Test it!

True

False

Enter a text in the input above to see the result

Test it!

True

False

Enter a text in the input above to see the result

Notes on password regex validation

While this regex validation is better than nothing, in situations when additional security is needed you should also check the password entered for a set of commonly used passwords like:

  • .Qwerty1
  • !Q1w2e3r4
  • etc

One good list can be found here.