Regular expressions (regex) are powerful pattern-matching tools used in programming, text processing, and data validation. Our free Regex Tester lets you write a regex pattern and instantly see all matches highlighted in your test string.
The tool shows every match with its position, matched text, and any captured groups. It supports all JavaScript regex flags including global (g), case-insensitive (i), multiline (m), dotAll (s), and unicode (u).
Whether you are developing validation patterns, parsing log files, extracting data, or learning regex, this tool provides instant, visual feedback on how your patterns work. Everything runs in your browser.