Regex Tester

Testing JavaScript regular expressions

This tool runs your pattern against the test string using the browser's native RegExp engine — the exact same engine your JavaScript code will use at runtime, so what you see here is exactly what you'll get in production.

Common flags

• g — find all matches instead of stopping at the first one (enabled automatically here so you always see every match).
• i — case-insensitive matching.
• m — ^ and $ match the start/end of each line, not just the whole string.
• s — lets . match newline characters too.
• u — treats the pattern as a sequence of Unicode code points.

FAQ

Why do numbered groups show as $1, $2...?

That's the standard reference syntax for capture groups in JavaScript replacement strings — group 1 is the first (...) in your pattern, in order.