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Merge CSV Files

Free tool to merge two CSV files into one — columns are unioned and rows stacked — in your browser.

Learn more: CSV Files ExplainedThe CSV format, RFC 4180 quoting rules, encodings, common pitfalls, and how CSV compares to TSV, JSON and Parquet.

CSV ACSV B

Result

Runs entirely in your browser — nothing you enter is uploaded or stored.

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Merge CSV Files

Free tool to merge two CSV files into one — columns are unioned and rows stacked — in your browser.

All processing happens in your browser — your files never leave the page, which you can confirm from the Network panel or our privacy policy.

Frequently asked questions

How do I use the Merge CSV Files?

Paste your two CSV files (A and B) and the result appears below. Everything runs in your browser.

Is my data uploaded anywhere?

No. This tool runs entirely in your browser — your CSV files are never sent to a server.

Is the Merge CSV Files free?

Yes — completely free, no sign-up and no limits.

Merge CSV Files

Frequently asked questions

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