How do I add line numbers?

Paste your text into the input area. Line numbers are prepended to each line instantly. Customise the starting number, separator style, and whether numbers are zero-padded.

What separator styles are available?

Choose from a period and space (1. line), a colon and space (1: line), or a tab character (1 line). The separator appears between the line number and the line content.

Can I start numbering from a number other than 1?

Yes — set the starting number to any positive integer. This is useful when adding numbers to a continuation of a larger file.

What does zero-padding do?

Zero-padding aligns line numbers by width — for example 001, 002, ... 010 instead of 1, 2, ... 10. The padding width is automatically set to match the total number of lines.

Is my text sent to a server?

No — the line numbering runs entirely in your browser. Your text is never transmitted anywhere.

Add Line Numbers

Prepend line numbers to each line of text instantly. Customise the starting number, separator (period, colon, or tab), and optional zero-padding.

Your files never leave your device

Start number

Separator

Zero-pad line numbers

Input (0 lines)

Output

How to Add Line Numbers

Paste your text into the input area.
Set the starting line number (default 1).
Choose a separator: period and space, colon and space, or tab.
Enable zero-padding to align line numbers to the same width.
Copy or download the numbered output.

Why Use This Tool?

Line numbers are essential when referencing specific lines in code reviews, technical documents, or log files. This tool adds them instantly without opening a code editor.

Add Line Numbers

How to Add Line Numbers

Why Use This Tool?

Frequently Asked Questions