Free Regular Expression Tester

Test and debug regular expressions. Free, fast, and private—all processing happens in your browser.

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Regular expressions are powerful tools for pattern matching and text manipulation. Our tester helps you build and debug regex patterns with instant visual feedback.

Features

- **Real-time Matching**: See matches highlight as you type - **Match Information**: View all matches with their positions - **Flag Support**: Toggle g, i, m, s, u flags - **Capture Groups**: View captured groups for each match

Common Regex Patterns

- **Email**: ^[\w.-]+@[\w.-]+\.\w+$ - **URL**: https?://[\w.-]+(?:/[\w.-]*)* - **Phone**: \d{3}[-.]?\d{3}[-.]?\d{4} - **IP Address**: \d{1,3}(\.\d{1,3}){3}

Frequently Asked Questions

What regex flavor is used?

This tool uses JavaScript regular expressions (ECMAScript). Most patterns are compatible with other languages, but some features may differ.

What are regex flags?

Flags modify how the regex works: g (global), i (case-insensitive), m (multiline), s (dotAll), u (unicode), y (sticky).

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