CSV tools

Merge CSV files

Combine several CSV files into one in your browser. Match columns or build a union. No account required.

Drop CSV files here

Or choose files. Nothing is uploaded automatically.

Choose CSVs

No files selected yet.

Merge modeSame columnsEvery file must contain the same column names. Column order may differ and is normalized to the first file.Union columnsBuild the union of all column names. Missing values become empty cells.

Output encodingUTF-8 with BOMOften opens more reliably in Excel on Windows.UTF-8Plain UTF-8 without a BOM.

Limits: up to 20 files, 10 MB per file, 30 MB total, 200000 rows, 200 columns.

What CSV merge does

Merge CSV combines multiple CSV files into one downloadable file. You choose the file order and whether columns must match or form a union. Processing runs in your browser.

How to merge CSV files

Select or drop the CSV files you want to combine.
Reorder the list so row groups appear in the sequence you need.
Choose Same columns or Union columns, then tap Merge CSVs.
Download merged.csv when the result is ready.

Same columns and union columns

Same columns keeps the first file’s header as the canonical order and remaps later files when names match but order differs. Union columns builds one header from all column names and fills missing cells with blanks.

Local browser processing

This tool processes CSV files in your browser. It does not upload CSV files to BizNavi Hub servers for merging. Leaving or refreshing the page clears in-memory files.

Encoding and BOM

Input supports UTF-8 and UTF-8 with BOM. If UTF-8 decoding fails, some browsers can read Shift_JIS without a heavy encoding library. Output defaults to UTF-8 with BOM for safer Excel interoperability; plain UTF-8 is available.

Limits

To keep browsers stable we limit file count, total size, rows, and columns. If you hit a limit, reduce files or split large datasets first.

Common business use cases

Combine monthly export CSVs into one working file.
Append regional sales CSVs that share the same columns.
Union slightly different export schemas before analysis.

Limitations

This tool does not open Excel workbooks (.xlsx), does not silently invent column names, and does not convert arbitrary encodings beyond UTF-8 and best-effort Shift_JIS. Very large files may fail on low-memory devices.

FAQ

Can I merge CSV files with different column order?: Yes. In Same columns mode, matching names are remapped to the first file’s order.
What if column names differ?: Use Union columns. Missing values become empty cells. Same columns mode reports an error instead.
Are my files uploaded?: No. Merging runs in your browser. BizNavi Hub does not receive CSV contents for this step.
Does the output work in Excel?: UTF-8 with BOM is the default to improve Excel opening on Windows. You can choose plain UTF-8 instead.
Is XLSX supported?: Not in this phase. Use CSV exports for now.

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