Regex Editor & Tester

Matches the first character of any non-empty line by anchoring at the line start (^ with the multiline flag) and requiring a non-newline character to follow. Truly empty lines (containing only a line break) are skipped because no character exists to satisfy [^\n]. Commonly used to find insertion points for adding prefixes, indentation, or line numbers while ignoring blank lines. Note that lines containing only whitespace (spaces or tabs) will still match.