Regex Tester

A regular expression is a sequence of characters that defines a search pattern. It is used to find, match, and manipulate text in programming languages, text editors, and command-line tools.

This tool supports the standard JavaScript regex flags: g (global — find all matches), i (case-insensitive), m (multiline), s (dotAll — dot matches newlines), and u (unicode).

Enter your regex pattern in the Pattern field, add any flags, then type or paste your test string. Matches are highlighted in real time as you type.

Common reasons: missing the 'g' flag for multiple matches, unescaped special characters (use \ before . * + ? etc.), or incorrect flags. Check the error message shown below the pattern field.