How it works
Prefix each line with its 1-based line number
Input definitions
- Your text
- Plain text; maximum 200,000 characters.
A worked example
- Your text
- Hello world
1. Hello world
Assumptions & limits
Unicode plain text only. No input is uploaded. Maximum 200,000 characters.
Sources & review
Maintained by AnsRio. Methods and examples use automated checks; this does not imply independent professional certification.
Method updated 2026-10-17. Content checked against the stated method and examples. Our verification approach.
Common questions
Can I paste formatted documents into this text tool?
The tool processes plain text. Styling, document structure and rich-text metadata are not preserved. Copy the result before closing the page.
How does the Add line numbers tool work?
Prefix each line with its 1-based line number.
What are the assumptions and limits of Add line numbers?
Unicode plain text only. No input is uploaded. Maximum 200,000 characters.