Add Line Numbers
Number each line.
Input Text
Output Text
What It Does
The Add Line Numbers tool automatically prepends sequential numbers to each line of your text. This is useful for referencing specific lines in documents, code reviews, or when organizing lists that need numbered references.
Common Use Cases
- Adding line numbers to code snippets for documentation or tutorials
- Numbering paragraphs or items in legal documents
- Creating numbered lists from plain text content
- Preparing text for code reviews where line references are needed
- Organizing meeting notes or action items with numbered references
How to Use
- Paste or type your text into the input area
- The tool automatically adds line numbers to each line
- Copy the numbered output for use in your documents
Features
- Instant line numbering as you type
- Works with any text content
- Preserves original text formatting
- Easy copy functionality for quick export
Edge Cases
- Very large inputs may take a few seconds to process in the browser. If performance slows, split the input into smaller batches.
- Mixed formatting (tabs, line breaks, or inconsistent delimiters) can affect output. Normalize spacing first if needed.
- Add Line Numbers follows the selected options strictly. If the output looks unexpected, re-check option settings and input format.
Troubleshooting
- Output looks unchanged: confirm the input contains the pattern this tool modifies and that the correct options are selected.
- Output differs from a previous run: confirm that the input and every option match, because deterministic tools should repeat when the settings are identical.
- Unexpected characters: check for hidden whitespace or encoding issues in the input and try normalizing first.
- Slow processing: reduce input size or try a modern browser with more available memory.
Frequently Asked Questions
Does this tool store or save my text?
No, all processing happens entirely in your browser. Your text is never uploaded to any server, stored, or logged. This ensures complete privacy and security for sensitive content.
Can I customize the numbering format?
The tool provides standard sequential numbering starting from 1. While the basic version uses a standard format, the output is plain text that you can easily modify if you need different formatting.
What happens to empty lines?
Empty lines are numbered just like any other line. If a line exists in your input (even if it's blank), it receives a sequential number, maintaining the exact structure of your original text.
Is there a limit to how many lines I can number?
The tool can handle extremely large documents with thousands of lines efficiently. Browser performance is the only practical limit, and modern browsers can easily process documents with tens of thousands of lines.
Does this work on mobile devices?
Yes, the tool is fully responsive and works on smartphones and tablets. The interface adapts to smaller screens while maintaining full functionality.
Can I use this for commercial documentation?
Absolutely. This tool is free for both personal and commercial use. Many professionals use it for creating technical documentation, user manuals, and business reports.