Regex Tester
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Free Online Regex Tester
Test regular expressions with real-time highlighting in your browser. No signup, no upload — 100% private.
All processing is done locally in your browser. Your data never leaves your device.
How to Use Regex Tester
- Enter your regular expression pattern.
- Set the flags (e.g., g for global, i for case-insensitive).
- Enter your test text and see matches highlighted instantly.
Key Features
- Real-time regex matching with highlighting
- Customizable flags
- 100% client-side processing
- Works offline
Frequently Asked Questions
What regex engine is used?
The tool uses JavaScript's built-in regex engine. It supports all standard regex patterns including lookaheads, lookbehinds, and named capture groups.
What flags can I use?
Common flags include g (global), i (case-insensitive), m (multiline), s (dotall), and u (unicode).
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