Merge toolLocal processingHeader-aware row merge

Merge CSV

Merge CSV files by keeping the first header and appending rows from later files.

Accepted files

CSV

Add at least two valid files. The first valid file sets the format for this merge batch.

Files to merge

Use Move up and Move down to choose output order.

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Drop files here

Upload multiple CSV files, arrange them, then merge into one download.

No files added yet.

What this tool does

Merge CSV stacks several CSV files into one, keeping a single header row and appending every file's data beneath it. It is built for same-schema exports like monthly reports, so you end up with one clean table instead of a dozen files, and a repeated header from a later file is skipped automatically.

How it works

Add your CSV files, set the order, and the tool reads them as text and appends the rows in your browser. The first file's header is kept and matching duplicate headers in later files are skipped. The merged CSV downloads as merged.csv. Nothing is uploaded.

When to use Merge CSV

Combining monthly or weekly CSV exports
Stacking same-schema spreadsheet data
Building one dataset from many files
Merging CSVs without uploading the data