Data Tools
CSV Merger
Combine multiple CSV files into one — header deduplication included. Free, browser-based, no signup.
No uploadsInstant merge
Click to add CSV files
Add multiple files one batch at a time
How to merge CSV files
- Click the upload area to select two or more CSV files.
- Enable "Skip header rows from 2nd file onward" if all files share the same column structure.
- Click Merge CSV Files to combine them.
- Download the merged file as a single .csv.
Privacy — your data stays local
All merging happens in your browser. Your files are never uploaded to any server.
Frequently Asked Questions
Do all CSV files need the same columns?
For best results, yes. The tool uses the header row from the first file and skips header rows from subsequent files. If columns differ, the data will still merge but may have misaligned columns.
How many files can I merge at once?
There is no hard limit — merge as many files as your browser memory allows.
Will the order of rows be preserved?
Yes. Rows are appended in the order the files were added.
Can I re-order the files before merging?
Currently, files are merged in the order they were added. Remove and re-add files to change the order.