CSV File Merger

About this tool

The CSV merger combines several files into one. Stack them vertically to append rows from multiple exports, or join them horizontally to line up columns side by side. It accepts CSV and Excel files in the same batch.

It is a quick way to pull monthly order exports into a single sheet, or to combine product lists from different suppliers before importing. Merging happens in your browser, so even large files stay on your device.

How to use it

1. Upload your filesAdd two or more .csv or .xlsx files.
2. Choose merge directionStack rows vertically to append data, or join columns horizontally to combine fields.
3. Download the combined fileGet one CSV with every file merged in the order you added them.

Frequently asked questions

What is the difference between vertical and horizontal merge?

Vertical stacks rows, so three 100-row files become one 300-row file — run the result through the CSV Deduplicator if the same row shows up in more than one export. Horizontal joins columns side by side, so files with the same rows gain extra fields.

Do the files need matching headers?

For a vertical stack, matching headers keep columns aligned. Mismatched headers still merge, but the columns will not line up, so tidy the headers first.

Is there a file count limit?

No fixed limit. The practical ceiling is your browser's memory, which handles dozens of typical exports without issue. If the merged file ends up too large for another app's import limit, break it back down with the CSV Splitter.