Merge CSV files

Columns are lined up by their header names, not by position. The merged file gets every column that appears in any of the inputs, so if one file has an extra column, rows from the other files simply leave it empty. Nothing is dropped.

Turn on the source column to add a field with each row's original file name. It's useful when you merge monthly exports, one file per store or region, or survey results from several forms, and still want to filter by origin later.

Header names must match exactly to line up, so "Email" and "email" become two columns. Rename headers to match before merging if needed. If the files are messy, the CSV cleaner can remove blank rows and duplicates from the merged result.

Merge CSV stacks rows into one table. To keep each file as its own sheet in a workbook instead, use CSV to Excel.

Exports from several systems are combined on your device, not on a server. The work happens in your browser, so nothing is uploaded and nothing is stored on a server. Once the page has loaded it keeps working offline, and it's free, with no sign-up and no watermark.