Overview
Add Line Numbers helps you prefix each line with its line number. This guide focuses on practical workflows, common pitfalls, and copy/paste friendly examples.
Use cases
- Clean up lists (trim/dedup/sort) before feeding them into scripts.
- Generate IDs/passwords for test fixtures.
Common pitfalls
- CRLF vs LF line endings can change results.
- Sorting is lexicographic; numbers may need padding.
FAQs
Does this upload my data?
No. By default, tools run locally in your browser.
Why is my input invalid?
Most failures are caused by non-standard formats, hidden whitespace, or truncated strings. Simplify the input and retry.
Examples
Input
a b a
Output
a b