What is a Line Number Generator?

A line number generator takes text (one or more lines) and adds a line number at the start of each line. You get output like 1 | first line, 2 | second line, and so on. It is useful for code snippets, log files, reference documents, or any place where you need to refer to lines by number.

This tool runs entirely in your browser. No data is sent to any server, so it is safe for sensitive or private content.

How it Works

1. Paste or type your text into the input field. Each line becomes one numbered line in the output.
2. Set options: Start number (e.g. 1), separator (pipe, spaces, dot, or paren + tab), and whether to pad numbers for alignment.
3. View the result in the output field. Numbers are added at the start of each line.
4. Copy the result with one click. The output updates as you type or change options.

Line endings (\n, \r\n, \r) are normalized so every line is numbered correctly.

Options

• Start number: The number assigned to the first line (default 1). Use a higher value if you are continuing from a previous block (e.g. start at 100).
• Separator: What appears between the number and the line text. Pipe (|) is common and readable; spaces give a simple gap; dot or paren + tab mimic some editor styles (e.g. 1. or 1) with a tab).
• Pad numbers: When on, line numbers are right-aligned (e.g. 1, 10, 100) so the text column lines up. When off, numbers are not padded.

Use Cases

• Code snippets: Add line numbers to paste into docs, tutorials, or support replies so you can say "see line 5".
• Logs: Number log output for easier reference in tickets or discussions.
• Lists: Number a list (tasks, items) for reference without editing the original.
• Teaching: Provide numbered text for exercises ("answer referring to line 3").
• Data / CSV: Add row numbers to a column of values for debugging or reference.

Frequently Asked Questions