Rename CSV Columns, free in your browser

Change CSV or TSV header names while keeping all rows and cell values in place.

How to rename CSV columns

1. Choose a CSV or TSV file with a header row.
2. Enter a new name for each column.
3. Review and download the renamed CSV.

Limits & good to know

• CSV and TSV files up to 50 MB are processed on your device.
• Column names must be unique; blank names receive a default column label.

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.

Will renaming a column change its data?

No. Only the first row’s column names change; the data rows remain the same.

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.