Free CSV Merger
Combine several CSV files with the same columns into one file - the header is kept once, and every file's rows are stacked underneath. Looking to merge columns instead of files? Try the CSV Column Merger.
No files loaded yet. Select two or more CSV files with matching columns.
How to merge CSV files
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1
Select your CSV files
Click "Browse for CSV files" and choose two or more files with matching columns.
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2
Check the options
Confirm the delimiter and whether each file starts with a header row.
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3
Click "Merge files"
All rows are stacked into one CSV, ready to copy or download.
Example use cases
Combining monthly exports
Merge a series of monthly CSV exports with the same columns into one combined file.
Consolidating data from multiple sources
Stack CSVs exported from different tools or teams into a single dataset.
Rebuilding a file after splitting it
Combine parts produced by a CSV splitter back into one file.
Frequently asked questions
Do the files need identical columns?
They should have the same columns in the same order for the merge to line up correctly. If a file has extra or missing columns, its rows will still be appended but may not align under the right header.
What happens to each file's header row?
With "Each file has a header row" checked, only the first file's header is kept at the top of the merged output; the header row from every other file is skipped.
What does the "source_file" column do?
When enabled, an extra column is added to every row recording which original file it came from - handy for tracing rows back after merging.
Is my data uploaded anywhere?
No. Files are read and merged locally in your browser using JavaScript - nothing is sent to a server.