Add Line Numbers

Prefix every line of text with its line number instantly — perfect for code listings, transcripts, and references. Free, client-side numbering tool.

🔒 100% Client-Side Processing

Your data is processed entirely in your browser and never transmitted to any server.

0 / 100M Limit

Common Use Cases

Referencing code in reviews

Number a snippet before pasting into a doc or chat so feedback can point at "line 14" unambiguously.

Preparing transcripts and depositions

Add citable line numbers to interview transcripts and legal documents.

Creating numbered checklists

Convert a plain list of steps into a numbered procedure in one paste.

Frequently Asked Questions

What format are the line numbers?
Each line is prefixed with its 1-based number, a period, and a space — "1. first line". The numbering restarts from 1 each time you run the tool on new input.
When would I number lines?
Referencing specific lines in code reviews or documentation, preparing legal or transcript documents with citable line references, and creating ordered lists from plain text in one step.
Is my data private when I use this tool?
Yes. This tool runs entirely in your browser using client-side JavaScript — nothing you type is transmitted to, logged by, or stored on any server. You can safely process confidential text, tokens, or code.