Number Lines
Prefix every line with a number, in whatever style you need.
Free No signup Runs in your browser — nothing uploaded
Result
What it does
Number Lines operates on the text you paste, line by line, and shows the result as you type. Nothing is sent anywhere and there is no length limit beyond what your browser will hold.
When you need it
The kind of tidying that is tedious by hand and error-prone in a spreadsheet: a list pasted out of an email, an export with inconsistent casing, a column of addresses with duplicates in it.
Limits and caveats
Line endings are normalised, and leading and trailing whitespace is treated as significant unless the tool says otherwise. Nothing is stored: reload the page and the text is gone. Everything happens in your browser, so the file never leaves your device.
How to use the Number Lines
- Paste your content, or load a file.
- The result appears as you type.
- Copy or download the output.
Frequently asked questions
- Can I start from a different number?
- Yes — useful when continuing a list from another document.
- Do my files get uploaded?
- No. This tool runs entirely in your browser, so the file never leaves your device.