Add Line Numbers

How this calculation works

The tool splits your text on every line break and prefixes each line with its position, starting at 1. Numbers are right-aligned and zero-free padded to the width of the largest one, so the column stays straight whether you have 9 lines or 900. Blank lines are counted too, so the final number matches the line count your editor shows. The original text is never changed — the number and a single space are simply added in front of each line.

What the results mean

Padding

Numbers are padded with leading spaces to equal width, so 1 and 100 align neatly down the left edge and the text after them stays in one column.

Line count

The last number is the total number of lines, including any trailing blank line — useful for confirming a file has the length you expect.

Blank lines

Empty lines still receive a number, so the numbering never skips and lines up with the same line in your editor or a diff.

Common problems and fixes

The numbers don't line up when I paste them somewhere

Alignment relies on a fixed-width font. In a proportional font the padding spaces are narrower than the digits, so the column drifts. Viewed in a monospace context — a code block or a plain-text editor — the column squares up.

I need to remove the numbers again later

This tool only adds them. To strip a leading number column in your editor, find-and-replace the regular expression ^\s*\d+\s to nothing — that removes the number and the space after it from the start of every line.

Frequently asked questions

More in Text

• Remove Line BreaksJoin wrapped text into a single flowing line.
• Whitespace CleanerCollapse extra spaces and trim every line.
• Sort LinesSort lines of text alphabetically, ascending or descending.