#️⃣ Line Number Formatter
Format line numbers with custom padding, prefix, and suffix. Advanced line numbering control — all in your browser, no upload, instant results.
About the Line Number Formatter
This line number formatter runs entirely in your browser. Type or paste text into the input box, configure the numbering options, and click Format to add line numbers to every line. Nothing is uploaded to a server — the conversion happens instantly with JavaScript on your device.
Options
- Start at — The number assigned to the first line (default 1).
- Step — How much the line number increases per line (default 1).
- Zero-pad width — Pads the number with leading zeros to this width (default 3, so
1becomes001). - Prefix — Text added before the number (optional).
- Suffix — Text added after the number and before the line content (default
". ").
How to use the formatter
- Paste or type your text in the input box.
- Adjust the numbering options to your liking.
- Click Format to add line numbers.
- Click Copy to copy the result, or Clear to start over.
Frequently asked questions
Does this tool upload my text? No. All conversion happens locally in your browser. Your text never leaves your device.
Can I start numbering from a number other than 1? Yes. Set "Start at" to any number you want, and use "Step" to control how much each line increments.
Can I use a prefix like a bullet or bracket? Yes. Enter any text in the "Prefix" field, such as [ or -.
Is there a length limit? The only limit is your browser's available memory. Even very long texts format instantly.