Free Online Regex Tester & Debugger
Test regular expressions in real-time with highlighting. Validate patterns, capture groups, and debug your regex instantly.
Real-time Testing
See matches instantly as you type your regex pattern or test string.
Visual Highlighting
Matches and groups are clearly highlighted in the text for easy debugging.
Detailed Match Info
View capture groups, indices, and full match details in a structured list.
Secure & Client-side
Your regex and text are processed 100% in your browser. No data is sent to any server.
The Ultimate Online Regex Tester & Debugger
Master the art of pattern matching with our advanced Regex Tester. Whether you are a seasoned developer or just learning regular expressions, our tool provides immediate visual feedback to help you validate and debug your patterns efficiently.
Why Use a Regex Tester?
Regular expressions (regex) are incredibly powerful for searching, extracting, and replacing text data. However, they can be cryptic and prone to errors. A dedicated testing environment allows you to:
🔍 Instant Validation
Don't wait for your deploy pipeline to fail. Test your regex against edge cases instantly in the browser.
🛠 Debug Complex Patterns
Isolate capture groups and verify that you are extracting exactly the data you need.
Quick Reference: Common Regex Tokens
| Token | Description | Example Matches |
|---|---|---|
| . | Any character (except newline) | a, 1, % |
| \w | Word character | a-z, A-Z, 0-9, _ |
| \d | Digit | 0-9 |
| [abc] | Character set | a, b, or c |
| * | Zero or more quantifier | "aa" in "baac" |
| + | One or more quantifier | "a" or "aaaa" |
Built for Modern Development
Stop guessing. Start matching. Our regex tester supports all modern JavaScript flags including Unicode properties, making it compliant with the latest ECMAScript standards.