Test and debug regular expressions in real time. See all matches highlighted in your test string. View capture groups, match indices, and flags. Includes a quick-reference cheat sheet.
This tool uses JavaScript's built-in RegExp engine. The syntax is ECMAScript-compatible, which covers most common regex patterns.
Flags modify how the pattern matches: 'g' (global) finds all matches, 'i' is case-insensitive, 'm' makes ^ and $ match line boundaries, 's' makes . match newlines, and 'u' enables full Unicode matching.
Parentheses () in a pattern create capture groups, which extract specific portions of the match. Named groups use (?<name>...) syntax. Each match's groups are shown in the results.
Yes. The regex engine runs entirely in your browser. Your patterns and test strings are never sent to any server.