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Merge CSV files

Combine monthly exports, survey results or contact lists into a single CSV. Columns are matched by their header, even in a different order, and you can add a column saying which file each row came from.

Runs in your browser. Your files are never uploaded or stored.

    Something not working, or missing an option?

    How to use Merge CSV files

    1. Choose or drop the CSV files.
    2. Put them in order and choose whether to add the file name as a column.
    3. Select Merge CSV to download merged.csv.

    Questions

    What if the files have different columns?

    Every column appears once in the result. Rows from a file without that column leave it empty.

    Are my files uploaded?

    No. The tool runs inside your browser, and the page is blocked from sending data anywhere. You can check by turning off your internet connection: it keeps working.

    Open-source parts

    This tool uses only features built into your browser: no third-party code.

    Full license texts

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