Regex Tester
Test regular expressions live. Enter a pattern and test string to see all matches highlighted inline, with captured groups listed. Supports all JavaScript regex flags: g (global), i (ignore case), m (multiline), s (dotAll).
Ctrl+Enter to run · Ctrl+K to switch tools · Recent button shows input history
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Which regex engine is used?
JavaScript's built-in RegExp engine (ECMAScript standard). Supports lookaheads, backreferences, named groups, and Unicode properties.
Why am I getting no matches?
Common causes: missing i flag for case-insensitive matching, anchors ^ and $ not matching as expected without the m flag, or special characters not escaped (use \d not d, \. not .).