Merge CSV Files
Combine multiple CSV files into one, matching up columns automatically. Everything runs in your browser — nothing is uploaded anywhere.
Upload
Drop in two or more CSV files, or add them one at a time.
Configure
Choose how columns line up and whether to drop duplicate rows.
Merge
Files are combined instantly, right in your browser.
Download
Preview the result, then export one clean, ready-to-use CSV.
Every column from every file is kept; missing values are left blank.
Why This Tool
Why Use Our CSV Merger?
Built for speed, privacy, and real control over exactly how your data comes together.
100% Private
Your files are processed entirely on your device. Nothing is ever uploaded to a server.
Smart Column Matching
Automatically aligns columns across files, even when headers are ordered differently.
Flexible Merge Options
Merge on every column or only the ones all files share, with optional duplicate removal.
Instant, No Limits
No file caps, no sign-up, no server queue to wait on — merge as many files as you need.
Preview Before You Export
Search and review the merged result before downloading, so there are no surprises.
Clean CSV Output
Get back a properly formatted CSV, ready to open in Excel, Sheets, or your own tools.