Match Debugger

Debug regex matches: see start index, end index, length, and matched text for each match.

About this tool

Same inputs as Regex Tester (pattern, test string, flags). Results are shown in a debug table: start index, end index, length, matched text, and capture groups. Use this when you need character positions for debugging or tooling.

Flags:
Click "Debug" to run the regex and see match positions (start, end, length).