Free

CSV Merge Tool

Combine multiple CSV files into one unified dataset

Browser-onlyNo uploadsInstant

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FAQ

How many CSV files can I merge at once?

You can merge up to 20 CSV files at once. For very large files (over 50MB each), consider splitting them first using our CSV Split Tool and merging in batches.

What happens if my CSV files have different column names?

The tool aligns columns by name. Columns that exist in some files but not others will be included with empty values for the files where they're missing. Column matching is case-insensitive.

Will the merged file have duplicate headers?

No. The tool automatically detects and removes duplicate header rows from each file beyond the first. Only one header row appears in the merged output.

Is my data uploaded to a server when I merge CSV files?

No. All merging happens entirely in your browser using JavaScript. Your CSV files never leave your device. Once you close the page, the data is gone.

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