Add Line Numbers

How each line gets its number

The text is split on line breaks (Windows or Unix) and every line is rewritten as the number, then the separator, then the original line. You control four things: the starting number, the separator string, zero-padding and whether to skip empty lines. The separator is inserted exactly as typed, so . , ) , : and | all work, and so does an empty field if you want numbers glued to the text.

Padding rule

With "Pad with zeros" on, the width is worked out from the highest number that will be printed, not from a fixed setting. Ten lines starting at 1 give two-digit numbers, so ten steps become:

01. Step 1
02. Step 2
...
09. Step 9
10. Step 10

Starting at 95 with ten lines tops out at 104, so every label is three digits wide and begins 095. Equal widths keep monospaced columns aligned and make the lines sort correctly as plain text.

Skipping empty lines

When "Skip empty lines" is ticked, blank (or whitespace-only) lines are passed through unnumbered, and they do not use up a number. Numbering alpha, a blank line, beta, gamma with ) as the separator gives:

1) alpha

2) beta
3) gamma

With the option off, the blank line would take number 2 and its own label (2) ), and the last two lines would become 3 and 4.

Edge cases

• The trailing newline. If the pasted text ends with a line break, that break only ends the last line: a two-line list ending in a break still gets numbers 1 and 2, and the final break is kept. Blank lines in the middle of the text are still numbered unless "Skip empty lines" is ticked.
• Numbers are plain digits. The tool does not produce roman numerals, letters or multi-level numbering such as 1.1 and 1.2. For letters or bullets, use Add Prefix and Suffix to Lines and type the marker yourself.
• It numbers lines, not sentences. A paragraph wrapped over three display lines is one numbered line unless it contains real line breaks. If you pasted hard-wrapped text, join it with Remove Line Breaks before numbering.
• Re-running stacks numbers. Numbering text that is already numbered adds a second set in front. Remove the old ones first with a regex in Find and Replace, for example ^\d+\. on a single line.

Common uses are numbering log excerpts so colleagues can refer to a line, numbering quiz questions, and turning a loose list into steps. To put the list in order first, use Sort Lines.