- Keeps the header from the first file and appends every data row in selected file order.
- Validates that every file has the same number and order of headings.
- Writes one new comma-separated UTF-8 CSV.
TRANSFORM TOOL · 07
Merge CSV Files
Combine matching CSV files into one table.
Select two or more CSV files with the same columns, validate their headers, and download one combined CSV.
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THE PROBLEM
How do I merge multiple CSV files?
Monthly exports and regional reports often share the same columns but arrive as separate files. Copying them together by hand risks repeated headers, missing rows, and columns moving into the wrong position.
- Rows are not sorted, deduplicated, cleaned, or matched by ID.
- Files with different headers are stopped rather than guessed into place.
- Every source file remains untouched.
HOW IT WORKS
Clear changes, no hidden guesses
Headers must match
Column names and order are checked before any rows are combined. A precise mismatch message identifies the file and column.
File order is row order
Rows from the first selected file come first, followed by each remaining file.
One header
Repeated heading rows are removed only at the boundary between selected files.