Paste text to number every line — choose the starting number, the separator, and whether to zero-pad the numbers to an equal width.
Add Line Numbers
🔒 Nothing you enter is sent anywhere or stored. All processing happens in your browser.
How it works
Numbering lines by hand is slow and breaks the moment you add or remove a line. This tool prefixes every line of your text with a running number, updating live as you type or tweak the options.
Set the Start number to begin at any value — 0, 1 or anything else. The Separator is the text placed between the number and the line, such as ". ", ") " or a tab; you can type whatever you like. Turn on Zero-pad to equal width so numbers line up neatly in a column: 1 becomes 01 or 001 depending on how many lines you have.
All processing happens in your browser, so code snippets, transcripts and private notes stay on your device.
Examples
Code snippet → separator ": " → numbered lines for a bug report.
Checklist starting at 0 → set start to 0 → zero-based numbering.
Long list → enable zero-padding → 001, 002, 003 that align perfectly.
Frequently asked questions
Can I start numbering from zero or another value?
Yes. The start number accepts any whole number, including 0 and negative values, and every following line increments from there.
What does zero-padding do?
It pads each number with leading zeros so they all share the same width — useful when you have more than nine lines and want them to line up in a column.
Can I use a tab or custom separator?
Yes. Whatever you type in the separator field is inserted between the number and the line, including spaces or symbols like ') '.
Does it renumber blank lines too?
Yes. Every line receives a number, including empty ones, so the count matches the text exactly.
Is my text uploaded?
No. Numbering happens entirely in your browser, so nothing you paste is sent anywhere.