Regex Tester

Type a regular expression and some test text below to see matches highlighted live, along with capture groups and match positions. Supports all standard JavaScript regex flags. Everything runs locally in your browser — nothing is uploaded anywhere.

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    Frequently asked questions

    Does this use JavaScript regex syntax?

    Yes, this tool uses the browser's native JavaScript RegExp engine, so it supports standard JS regex syntax and flags (g, i, m, s, u, y).

    Is my text uploaded anywhere?

    No, everything runs locally in your browser; nothing is sent to a server.

    What do the flags mean?

    g = global (find all matches), i = case-insensitive, m = multiline (^ and $ match line boundaries), s = dotall (dot matches newlines), u = unicode, y = sticky (match must start at lastIndex).

    How do capture groups work?

    Parentheses () in your pattern create capture groups; their matched values are listed below each match and can be referenced in the replacement using $1, $2, etc.