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Regex Tester & Validator
Test and validate regular expressions with real-time matching. Supports flags, groups, and common patterns.
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Common patterns:
Test regular expressions against sample text in real time. See matches highlighted as you type, with capture groups and match indices displayed for debugging.
How to use Regex Tester & Validator
- Enter your regex pattern in the pattern field and choose flags (g, i, m, s) as needed.
- Paste or type your test string in the input area.
- Review highlighted matches and capture group details in the output panel.
Features
- Live match highlighting as you edit the pattern or test string.
- Supports global, case-insensitive, multiline, and dotall flags.
- Displays capture groups and their match positions for debugging.
- Common regex reference cheat sheet included.
FAQ
Which regex flavor does this tester use?
It uses JavaScript's built-in RegExp engine, which covers most common patterns. Some advanced features like lookbehind vary by browser version.
Can I test regex with capture groups?
Yes. Capture groups are displayed with their matched values and positions so you can verify your pattern extracts the right data.
How do I match a literal backslash in regex?
Use \\ in the pattern. Backslash is an escape character in regex, so you need two backslashes to match one literal backslash.
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