Regex Tester with Live Highlighting

Type a JavaScript regular expression and a test string — matches highlight instantly as you type, with capture groups listed below. Uses your browser's native RegExp engine.

Pattern

g (global) i (ignore case) m (multiline)

Common patterns

Test string Matches highlighted

Matches

About this regex tester

This tester runs JavaScript's native RegExp, so results match exactly what your Node.js or browser code will do — including flag behavior and capture group numbering. Named groups, lookaheads, and all ES2018+ syntax your browser supports will work here too.