CSV Column Transformer
Rename, reorder, split, merge and clean up CSV columns — right in your browser. Nothing is uploaded anywhere.
Or paste CSV text on the right.
Merge columns
Pick two or more columns. They'll be joined in their current left-to-right order.
Columns
Rename, reorder, split or transform each column.
Preview
About the CSV Column Transformer
This free online tool lets you clean up and reshape CSV data directly in your browser — no upload, no sign-up, and no data ever leaves your device. Load a CSV file or paste CSV text, then rename, reorder, split, merge or reformat columns before exporting the result as CSV or JSON.
What you can do
- Rename columns — edit column headers inline.
- Reorder columns — move columns left or right with one click.
- Split a column — break one column into several using a separator.
- Merge columns — combine two or more columns with a custom separator.
- Clean up numbers and currency — strip symbols, fix decimals and round values.
- Reformat dates — convert dates into a consistent format.
- Undo / redo — step back through changes safely.
- Export — download the transformed data as CSV or JSON with a custom delimiter and filename.
How to use it
- Upload a CSV file or paste CSV data, then choose a delimiter and click Load Data.
- Use the column cards to rename, reorder, split, merge or transform each column.
- Check the live preview table to confirm the result.
- Pick an export format and delimiter, then download the file.
Frequently asked questions
Is my CSV data uploaded anywhere?
No. All parsing and transforming happens locally in your browser — your data is never sent to a server.
What CSV delimiters are supported?
Comma, semicolon and tab are supported, with an auto-detect option for import.
Can I export to a format other than CSV?
Yes. You can export your transformed data as either CSV or JSON.
Is there a limit to how many columns or rows I can process?
There's no fixed limit — performance depends on your browser and device, since everything runs client-side.