R
Regex Master
TutorialsToolsFAQAboutContact

Regex Debugger

Validate your patterns with a test-driven approach. Define multiple test cases to ensure your regex matches exactly what you want and nothing else.

Why use a Regex Debugger?

Complex regular expressions can be fragile. A small change might fix one case but break another. Our debugger allows you to:

  • Create a suite of test cases (both "should match" and "should fail").
  • Instantly see which tests pass and which fail as you type.
  • Inspect captured groups for every match.
  • Catch regressions before they reach your code.
//

Unit Tests

1
2
3
🔥

Popular Patterns

📧

Email Address

Validate standard email formats. Includes support for common domains and subdomains.

Try Email Regex →
📅

Dates (YYYY-MM-DD)

Match dates in ISO 8601 format. Validates year, month, and day structure.

Try Date Regex →
📱

US Phone Number

Match various US phone formats including dashes, dots, and parentheses.

Try Phone Regex →
🌐

IPv4 Address

Validate IPv4 addresses with proper range checking (0-255).

Try IP Regex →
R
Regex Master

Your comprehensive guide to mastering regular expressions through tutorials and tools.

Company

  • About Us
  • Contact
  • FAQ

Resources

  • All Articles
  • Popular Tools
  • Sitemap

Legal

  • Privacy Policy
  • Terms of Service
  • Cookie Policy
  • Disclaimer

© 2026 Regex Master. All rights reserved.