Combine CSV Files — Free, Without Uploading Them

Join hundreds of CSVs into one clean file. Skip repeated headers and remove duplicate rows — all on your computer, nothing uploaded.

Free · No signup · No upload · From the makers of Bulk File Merger, trusted since 2004

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Connected — privacy mode available

You don't need the internet. Disconnect and watch the tool work.

Online

or drop Excel, CSV, or text files here

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0 files loaded into your browser. Nothing has been uploaded.

Output filename Output format Skip header row on files 2+ Remove duplicate rows First sheet only (Excel)

Excel cell values are preserved. Charts, macros, conditional formatting, and merged cells are not.

What you can do

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Combine CSV files

Join hundreds of CSVs into one. Drag to set the order, click Merge, download — no row caps, no queue.

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Skip repeated headers

One checkbox drops the header row on files 2+ so your column names appear exactly once at the top.

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Output to Excel if you want

The combined file can download as .csv or as an .xlsx workbook — your choice.

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No upload wait

Runs locally on your computer. No queue, no upload bar, no row caps. Often faster than the online tools.

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Private by design

Your files stay on your device from start to finish. Turn off your Wi-Fi and the merge still works.

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Nothing to install

Works in the browser you already have — on desktop, laptop, or phone. No account, no download.

How we compare

	This tool	Online CSV mergers	Excel Power Query	Manual copy-paste
Files stay on your computer	✓ You can verify	Uploads	✓	✓
Handles Excel + CSV + text	✓	Usually one type	✓	✓
Drag to reorder before merge	✓	Rare	No	—
Setup required	None	None	Hours	None, but slow
Works offline	✓	No	✓	✓

Turn off your Wi-Fi. It still works.

That's how you know nothing ever leaves your computer.

Online mergers and "free file combiners" upload your data to a server. We don't. There's no test you can run on us that we'd fail.

Try it yourself ↑

Common questions

Will the repeated header rows be removed?

Yes — tick "Skip header row on files 2+" and the column names appear once at the top of the combined file instead of repeating between every file.

Is there a row or file limit?

No row caps and no per-file limits. Very large batches are bounded only by your device's memory; for routine multi-gigabyte jobs the desktop app is the better fit.

Do my files get uploaded?

No. Everything runs on your own computer. Disconnect from the internet and it keeps working — that's the proof.

My CSVs have different columns — what happens?

Files are stacked in order exactly as they are. If the column layouts differ, you'll see it immediately in the output — reorder or fix the inputs and merge again for free.

Merging thousands of files at a time?

This page is built for everyday merges. For multi-gigabyte batches and folder-scale jobs on a schedule of their own, the Bulk File Merger desktop app for Windows and Mac picks up where the browser leaves off.

See the desktop app →

Also free: Merge Excel files online · Merge text files · How to merge Excel files (guide) · Enjoying it? Leave a tip ☕

Works on every device you use

iOS, Android, macOS, Windows, or any modern browser — same tool, same code, same privacy.

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