Regex Tester
Test and debug regular expressions in real-time with match highlighting, capture groups, and detailed results. Free online regex tester for developers with examples, reference guide, and instant validation. No signup required.
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What is Regex Tester?
Regex Tester is an interactive tool for testing and debugging regular expressions (regex) in real-time. It highlights matches instantly, shows capture groups, explains pattern syntax, and supports multiple regex flavors including JavaScript, Python, and PCRE.
Key Benefits
- Real-time pattern matching
- Capture group highlighting
- Pattern explanation
- Multiple regex flavors
Common Use Cases
- •Pattern development
- •Text extraction
- •Form validation
- •Log parsing
- •Data cleaning
How to Test Regular Expressions
- Enter your regex pattern: Type your regular expression pattern in the pattern field. Use standard regex syntax—no need to add delimiters like /pattern/.
- Add test text: Paste or type the text you want to test against in the test string area. The tool highlights matches instantly.
- Set regex flags: Toggle flags as needed: g (global/find all), i (case-insensitive), m (multiline), s (dotall), u (unicode).
- Analyze results: View highlighted matches, capture groups, and match details. Use the explanation feature to understand what each part of your pattern does.
Key Features
- Real-time pattern matching and highlighting
- Support for all regex flags (g, i, m, s, u)
- Capture group visualization
- Match details with index positions
- Pattern explanation and breakdown
- Common pattern library