Test and debug regular expressions with live matching, explanations, and comprehensive analysis
beginnerDeveloper Tools
🔍 Regex Mode
//g
📚 Common Patterns
Email address validation
Validation^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$
Examples: user@example.com, test.email+tag@domain.co.uk
URL validation (HTTP/HTTPS)
Validation^https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&//=]*)$
Examples: https://example.com, http://www.site.com/path?query=value
Phone number (international format)
Validation^\+?[1-9]\d{1,14}$
Examples: +1234567890, 1234567890
Strong password (8+ chars, uppercase, lowercase, number, special char)
Validation^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$
Examples: MyPass123!, SecureP@ssw0rd
IPv4 address
Network\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b
Examples: 192.168.1.1, 10.0.0.1
Hexadecimal color code
Web#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})
Examples: #FF0000, #f00, #123ABC
Words in ALL CAPS
Text\b[A-Z]{2,}\b
Examples: HTML, CSS, JAVASCRIPT
Words followed by other words (lookahead)
Advanced\b\w+(?=\s+\w+)
Examples: hello world, regex testing
Dollar amounts (lookbehind)
Advanced(?<=\$)\d+(?:\.\d{2})?
Examples: $19.99, $100, $5.50
Valid IPv4 address (strict validation)
Network\b(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b
Examples: 192.168.1.1, 255.255.255.255
📝 Test Text
🎯 Quick Test Data
📚 Regex Quick Reference
🔤 Character Classes
\\dAny digit
\\wWord character
\\sWhitespace
.Any character
🔢 Quantifiers
*0 or more
+1 or more
?0 or 1
{n,m}n to m times
🎯 Anchors
^Start of string
$End of string
\\bWord boundary
\\BNon-word boundary
❓ Frequently Asked Questions
What is Regex Tester?
Free online regex tester and debugger. Test regular expressions with live matching, explanations, capture groups, and comprehensive analysis.
Is Regex Tester free to use?
Yes, Regex Tester is completely free to use. No registration or payment required.
Who can use Regex Tester?
Regex Tester is designed for developers, programmers, data analysts, system administrators and anyone who needs data validation, text processing, log analysis, form validation.
Can I test regex with different flags?
Yes, you can test with global (g), case-insensitive (i), multiline (m), and other regex flags.
Does it explain regex patterns?
Yes, the tool provides explanations for regex patterns and highlights matches in real-time.