Developer Tools
Regex Tester
Test regular expressions with live matching, capture groups, and detailed match information.
How to use
Enter your regex pattern, optional flags (g, i, m, etc.), and test text. Click "Run Tool" to see all matches with their positions and capture groups.
Example pattern
Pattern: (\w+)@(\w+)\.(\w+) Flags: gi
Example output
Found 1 match(es): Match 1: "test@example.com" at index 32 Group 1: "test" Group 2: "example" Group 3: "com"
FAQ
What regex flags are supported?
All JavaScript regex flags: g (global), i (case-insensitive), m (multiline), s (dotAll), u (unicode), y (sticky).
How do capture groups work?
Use parentheses () in your pattern to capture parts of the match. Each group is numbered and shown in the results.
Is regex execution safe?
Yes, regex is executed in your browser. Be aware that some patterns can be slow on large inputs (ReDoS vulnerability).