Can I delete more than one column at once?

Yes. Tick as many as you like and they all go in one pass; the preview shows the file as it will download, so nothing disappears unseen.

What happens to the columns I keep?

Nothing. Every value you did not touch is carried through exactly as written — leading zeros, long numbers, dates that look like words, quoting and line endings included.

Does the column order change?

No. The remaining columns keep exactly the order they had; deleting the third column simply closes the gap.

Can I undo a deletion?

Your original file is never touched — the tool produces a new download. Untick the column and the preview puts it straight back.

Why not just hide columns in Excel?

Hidden columns are still in the file, and the person you send it to can unhide them. If the point is that a column must not travel, it has to be gone, not hidden.

Is my file uploaded anywhere?

No. When you delete columns from a CSV here, the work happens inside this page and the browser is told to block outbound connections, so there is no upload to intercept. Watch the Network tab of your developer tools while you delete columns from a CSV: the only requests are for this site’s own code, and none carries your file.

Delete columns from a CSV

Tick the columns to drop and download the rest, byte for byte unchanged. Useful before sharing a file that holds more than the recipient needs.

Delete columns from a CSVRunning on your device

Source

Your file

or drag one here · it stays on your device

Result

Add a file. Tick the columns to remove and the preview shows the file as it will download.

How this works

Add your file. Drop a CSV onto the page.
Tick what goes. Choose the columns to remove and watch the preview.
Download. Save the file with only the columns you kept.

What it cannot do

Deleting a column removes it from the download only; your original file on disk is never modified.
A file whose header repeats the same column name shows each copy separately, so you can delete precisely the one you mean.
Removing a sensitive column is not anonymisation: other columns may still identify people. The column anonymiser on the roadmap is the tool for that job.

Questions

Can I delete more than one column at once?: Yes. Tick as many as you like and they all go in one pass; the preview shows the file as it will download, so nothing disappears unseen.
What happens to the columns I keep?: Nothing. Every value you did not touch is carried through exactly as written — leading zeros, long numbers, dates that look like words, quoting and line endings included.
Does the column order change?: No. The remaining columns keep exactly the order they had; deleting the third column simply closes the gap.
Can I undo a deletion?: Your original file is never touched — the tool produces a new download. Untick the column and the preview puts it straight back.
Why not just hide columns in Excel?: Hidden columns are still in the file, and the person you send it to can unhide them. If the point is that a column must not travel, it has to be gone, not hidden.
Is my file uploaded anywhere?: No. When you delete columns from a CSV here, the work happens inside this page and the browser is told to block outbound connections, so there is no upload to intercept. Watch the Network tab of your developer tools while you delete columns from a CSV: the only requests are for this site’s own code, and none carries your file.

Your file is processed in this page and never uploaded — the privacy page shows how to confirm that yourself.