Add Line Numbers

Yes. Change the "Start at" value to any number (including 0). The tool will begin numbering from that value and increment by one for each subsequent line.

Zero-padding adds leading zeros so all line numbers have the same width. For example, if you have 100 lines, line 1 becomes "001" and line 42 becomes "042". This keeps text neatly aligned in monospaced editors and code blocks.

When enabled, blank lines are left as-is without a number. The numbering sequence continues on the next non-blank line. This is useful for code or poetry where blank lines serve as visual separators.

Five separator options: dot (.), closing parenthesis ), dash (-), colon (:), and tab character. Each is followed by a space (or tab) so the text stays readable.

No. All processing happens entirely in your browser. No text is sent to any server, and the tool works offline once the page has loaded.