Regex Tester
Test and debug regular expressions with real-time matching and detailed results. Perfect for pattern validation and development.
Enter a regex pattern and some text below. Matches will be highlighted automatically.
Regular Expression Pattern
/
Test Your Pattern
3 matches
Input Text
Highlighted Matches
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Common Patterns
Why Use a Regular Expression Tester?
Regular expressions (regex) are powerful pattern-matching tools used in programming, data validation, and text processing. Our regex tester helps you develop and debug patterns efficiently:
- Test regex patterns in real-time with instant feedback
- Visualize matches with highlighting and detailed information
- Debug complex patterns with capture group analysis
- Experiment with different flags and modifiers
- Validate data formats like emails, URLs, and phone numbers
- Learn regex through interactive examples and common patterns
- Save time during development and debugging
How to Use This Regex Tester
Using our regex tester is straightforward:
- Enter your regular expression pattern in the pattern field
- Add flags (g, i, m, s, u, y) as needed for your use case
- Input or paste your test string in the test area
- View highlighted matches and detailed match information
- Click on matches to see capture groups and named groups
- Use common patterns as starting points for your own regex
Regular Expression Flags Explained
Regex flags modify how the pattern matching works:
- g (Global): Find all matches, not just the first one
- i (Ignore Case): Make the pattern case-insensitive
- m (Multiline): ^ and $ match line breaks, not just string start/end
- s (Dot All): . matches newline characters
- u (Unicode): Enable full Unicode support
- y (Sticky): Match only from the lastIndex position
Common Regex Use Cases
Regular expressions are essential in many development scenarios:
- Form validation (emails, phone numbers, passwords)
- Data extraction from text files and logs
- Search and replace operations in code editors
- URL routing and parameter extraction
- Input sanitization and security filtering
- Log file analysis and monitoring
- Data parsing and transformation
- Text processing and content analysis
Features of Our Regex Tester
- Real-time pattern testing with instant results
- Visual highlighting of matches in the test string
- Detailed match information with capture groups
- Support for all JavaScript regex flags
- Interactive flag toggles with descriptions
- Common pattern library for quick testing
- Error handling and validation feedback
- Copy pattern functionality
- Completely free with no registration required
- Privacy-focused - all processing happens in your browser