Regex Tester & Debugger

Type your regex pattern in the pattern field and paste your test string below. Matches are highlighted in real-time as you type. Toggle flags like global (g), case-insensitive (i), multiline (m), dotAll (s), and unicode (u) to fine-tune matching behavior.

This regex tester supports all standard JavaScript regex flags: g (global — find all matches), i (case-insensitive), m (multiline — ^ and $ match line boundaries), s (dotAll — . matches newlines), and u (unicode — full Unicode support).

Yes. When your regex contains capture groups using parentheses, the tool displays each numbered group ($1, $2, etc.) and named groups (?<name>...) separately so you can verify your pattern extracts the right data.

Switch to 'Replace' mode using the tab at the top. Enter your replacement string — you can use $1, $2 for numbered groups or $<name> for named groups. The result updates in real-time as you type.

Yes! Click the 'Share' button to generate a shareable URL that encodes your pattern, flags, test string, and replacement string. Anyone who opens the link sees the exact same regex test setup.

No. All regex matching runs entirely in your browser using JavaScript's built-in RegExp engine. Your patterns and test strings never leave your device.

This regex tester is designed to be lighter and faster. It loads instantly as a static page with zero server dependencies. Every feature — matching, replacing, capture groups, and sharing — works 100% client-side.