Data Tools

Add Line Numbers

Prefix every line with a line number. Choose 0-indexed or 1-indexed output. Free and private.

Updates as you type🔒Private · nothing uploaded

Start at 1 (instead of 0)

Input

Numbered Output

Prefix every line with a sequential number. Useful for code reviews, document collaboration, and referencing specific lines in large text files.

All processing happens in your browser. No text is transmitted or stored.

FAQ

Questions

Is my text uploaded to a server?+

No. All processing happens in your browser. Nothing leaves your computer.

Can I start numbering from 0?+

Yes. Uncheck the 'Start at 1' option to use 0-based indexing.

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