Add CSV Row Numbers, free in your browser

Insert a row_number column at the start of a CSV or TSV table and number records from 1 in their existing order.

How to add row numbers to a CSV

1. Choose a CSV or TSV file.
2. Preview the new row number column.
3. Download the numbered CSV.

Limits & good to know

• CSV and TSV files up to 50 MB are processed on your device.
• If a row_number header already exists, a unique row_number_2 header is used.

Frequently asked questions

Are my files uploaded to a server?

Your files are processed on your device, not uploaded to our servers. Your file and edits are saved in this browser for recovery, and previous documents remain in Saved drafts when you open another file. Use Saved drafts to resume or delete individual copies, or clear this site’s browser data to remove all copies. Browser storage can be cleared or become unavailable; download important work.

Are the header row and data rows both numbered?

No. Only data records are numbered; the header is left as a column label.

Is this really free, or free "until you hit a limit"?

Really free. Unlike most "free" PDF sites there is no task-per-day cap, no locked Pro features, no watermark stamped on your file, and no payment step before download. Every tool is the full tool.