Regex Tester

Test regular expressions with live match highlighting, capture groups, and substitution.

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Enter a regex pattern to see matches.

Frequently Asked Questions

What regex flavor does this use?
JavaScript's built-in RegExp engine, which follows the ECMAScript standard. Compatible with JavaScript, TypeScript, and many other languages.
Can I test multiline regex?
Yes. Enable the 'm' flag for multiline mode where ^ and $ match line boundaries, and 's' flag for dotAll mode where . matches newlines.
Is this tool free to use?
Yes, completely free. No account, no subscription, no hidden limits.
Are my files safe? Do you upload them?
Your files never leave your device. All processing runs locally in your browser using JavaScript — nothing is sent to any server.
Does it work on mobile?
Yes, it works on all modern browsers including mobile Safari and Chrome on iOS and Android.