About Merge CSV Files Online
Merge CSV Files Online is a free tool that combines several CSV files into one, right in your web browser. There is nothing to install, no account to create and no file to upload.
Why we built it
Exports from spreadsheets, CRMs, analytics platforms and databases often arrive in pieces. Combining them by hand means copying and pasting, repeated header rows, mismatched columns and encoding problems. Most online tools solve that by asking you to upload your data to a server. We wanted a faster and safer way, so the whole merge happens on your own device.
What makes it different
Private by design
Files are read and merged in your browser. They are never sent to our servers.
Handles real-world files
It detects delimiters, respects quoted fields and lets you match columns by header name or position.
Clean results
Remove duplicates, trim whitespace, skip blank rows and track which file each row came from.
Free for everyone
No sign-up, no watermark and no daily limit. It works on Windows, Mac, Linux and Chromebook.
How it works
When you add files, your browser reads them locally with JavaScript. The tool detects each file's delimiter, parses the rows, aligns the columns and writes a new CSV that you download or copy. Closing the tab clears everything from memory.
Get in touch
Found a bug, have a feature idea or a question about a file that will not merge? Visit the contact page. You can also read our privacy policy and terms and conditions.