Free Online Regex Tester & Debugger

Test regular expressions in real-time. See matches and capture groups instantly.

Regular Expression
Presets:
//g
Test String
Enter text to test against the regex
Matches
0 matches
Matches will be highlighted here...

How the Regex Tester Works

Our regex tester uses JavaScript's built-in regular expression engine to validate and test your patterns in real-time. As you type, matches are instantly highlighted and capture groups are displayed.

Features

Test patterns with global, case-insensitive, multiline, and dotAll flags. See individual matches with their positions and capture groups. Use preset patterns for common validations like email, URL, and phone numbers.

Privacy First

All testing happens locally in your browser. Your regex patterns and test data never leave your device.

Frequently Asked Questions

We use JavaScript regex engine which supports most common regex features including lookahead, lookbehind, capture groups, and Unicode. Some advanced features from PCRE may not be available.

g (global) matches all occurrences, i (case insensitive) ignores case, m (multiline) treats each line as separate, s (dotAll) makes . match newlines too.

Use parentheses () in your pattern to create capture groups. The matches panel will show each group separately, numbered from 1.

Yes, all regex testing happens locally in your browser. Neither your pattern nor test string is sent to any server.

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