Strong Password Regex - Pattern & Examples

Pattern Breakdown

Understanding the regex pattern ^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$:

        ^ - Start of string
$ - End of string
\d - Any digit (0-9)
.* - Any character, zero or more times
? - Optional (zero or one)
* - Zero or more
[...] - Character class
(...) - Capturing group
(?=...) - Positive lookahead
{n,m} - Quantifier (n to m times)

      

Examples

Input	Result	Explanation
`MyP@ssw0rd`	✓ Match	Meets all requirements
`Complex1!`	✓ Match	Minimum valid password
`password`	✗ No Match	Missing uppercase, number, special
`Short1!`	✗ No Match	Too short

Code Examples

JavaScript

const pattern = /^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$/;
const text = "MyP@ssw0rd";

// Test if string matches
if (pattern.test(text)) {
  console.log("Valid!");
}

// Extract matches
const matches = text.match(pattern);
console.log(matches);

Python

import re

pattern = r'^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$'
text = "MyP@ssw0rd"

# Test if string matches
if re.match(pattern, text):
    print("Valid!")

# Find all matches
matches = re.findall(pattern, text)
print(matches)

PHP

<?php
$pattern = '/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$/';
$text = "MyP@ssw0rd";

// Test if string matches
if (preg_match($pattern, $text)) {
    echo "Valid!";
}

// Find all matches
preg_match_all($pattern, $text, $matches);
print_r($matches);
?>

Java

import java.util.regex.*;

String pattern = "^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)(?=.*[@$!%*?&])[A-Za-z\\d@$!%*?&]{8,}$";
String text = "MyP@ssw0rd";

Pattern p = Pattern.compile(pattern);
Matcher m = p.matcher(text);

if (m.matches()) {
    System.out.println("Valid!");
}

Use Cases

Common applications: User registration, password reset, security compliance

Form validation and input sanitization
Data extraction and parsing
Search and replace operations
API request/response validation
Log file analysis

Frequently Asked Questions

What is the regex pattern for strong password regex?

The regex pattern is: ^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$. Validate strong passwords requiring: 8+ characters, uppercase, lowercase, number, and special character.

How do I use the strong password regex pattern in JavaScript?

In JavaScript: const regex = new RegExp('^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)(?=.*[@$!%*?&])[A-Za-z\\d@$!%*?&]{8,}$'); or const regex = /^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$/;

Does this pattern work in Python?

Yes, use: import re; pattern = re.compile(r'^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$') in Python. Most regex patterns are cross-language compatible.

What are common use cases for strong password regex?

User registration, password reset, security compliance

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