Regex Tester
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About this tool
What is Regex Tester?
A Regex Tester allows you to write and test regular expression patterns against sample text in real-time. It highlights matches, shows captured groups, and helps you debug complex patterns before using them in code.
Our tester supports all JavaScript regex flags: global (g), case-insensitive (i), multiline (m), and dotall (s). You can see all matches with their positions and any captured groups.
Regular expressions are powerful pattern matching tools used in search, validation, and text processing across all programming languages.
How to Use Regex Tester
- 1Enter your regex pattern (without delimiters)
- 2Set flags: global (g), case-insensitive (i), multiline (m)
- 3Enter test string to match against
- 4Click "Test Regex" to see all matches
- 5View captured groups for each match
- 6Refine pattern based on results
Use Cases for Regex Tester
Pattern Development
Build and test regex patterns before adding to code.
Email Validation
Test patterns for validating email addresses.
Data Extraction
Develop patterns to extract specific data from text.
Search Patterns
Create search patterns for find-and-replace operations.
Input Validation
Test patterns for form field validation.
Features
- Real-time matching
- Flag support
- Capture groups
- Match positions
- Syntax highlighting
- Error messages
- 100% Free - No signup required
- Instant results - No waiting
- Updated for 2026 - Latest data
- Privacy-first - Data never stored
Frequently Asked Questions about Regex Tester
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