Regex Tester — Test Regular Expressions
Free regex tester. Write and test regular expressions with live matching and detailed results.
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🔒100% Private — Your files never leave your device. All processing runs locally in your browser.
How It Works
Enter a regular expression pattern and flags, type or paste your test string. Matches are listed in real time with their position and value.
The tool uses JavaScript's native RegExp engine. As you type, it continuously tests your pattern against the input, highlighting all matches and showing capture groups. Perfect for debugging patterns before using them in code.
Features
- ✓Live matching as you type — instant feedback
- ✓Supports all JavaScript regex flags (g, i, m, s, u, y)
- ✓Match list with positions and capture groups
- ✓Error messages for invalid patterns
- ✓Syntax highlighting in pattern input
- ✓Copy regex or matches to clipboard
Frequently Asked Questions
JavaScript/ECMAScript regex syntax.