Line Numberer
Add sequential line numbers to text or remove existing line numbers.
Start at
Separator
Input
Output
About This Tool
The Line Numberer prepends a sequential number to each line of text, or strips existing line numbers from numbered text. In Add Numbers mode, configure the starting number, the separator between number and content, and whether to zero-pad so all lines are equal width.
In Remove Numbers mode, the tool strips any leading number and the selected separator from each line. All processing is instant and runs locally in the browser.
How to Use
- Choose Add Numbers or Remove Numbers mode.
- Paste text into the input area or click Sample.
- In Add mode, set the start number, separator, and zero-padding options.
- Output updates instantly — click Copy to copy the result.
Use Cases
Developers add line numbers to code excerpts for documentation or bug reports. Technical writers number steps in procedures. Editors number manuscript lines for proofreading. QA engineers number exported test cases.
FAQ
- Can I start numbering from 0? Yes. Set the start number field to 0.
- What does zero-padding do? Zero-padding ensures all numbers have the same digit width. For 10 lines starting at 1, numbers become 01, 02, … 10, keeping alignment in monospace fonts.
- Are blank lines numbered too? Yes, blank lines receive numbers as well. To skip blank lines, use the Text Sorter tool to remove them first.