Merge Two CSV Files
Online Free —
No Upload
Drop two CSV files and combine them into one — entirely in your browser. Columns are aligned automatically, duplicate headers are handled, and you can download the merged file instantly. No upload, no account, nothing leaves your device.
Open the CSV Merger
Drop File A and File B. Rawsort aligns the columns, stacks the rows, and lets you download the merged CSV immediately. Free, local, private.
Open the CSV Merger
Click the button above to go to the Rawsort CSV Merger. No account or signup needed.
Drop both CSV files
Drop File A into the left panel and File B into the right panel. Both files are read locally in your browser — nothing is uploaded.
Download the merged file
Click Merge Files. Rawsort stacks the rows, aligns columns by header name, and lets you download the combined CSV instantly.
No upload, fully private
Both CSV files are processed in your browser. No files are sent to any server. Your data stays on your device the entire time.
Smart column alignment
When your two files have different columns, Rawsort matches them by header name and fills missing cells with empty values. No data gets lost or misaligned.
Optional source column
Enable the source column option and Rawsort adds a column showing which file each row came from — useful when you need to trace data back after merging.
Can I merge two CSV files online without uploading them?
Yes. Rawsort's CSV Merger reads both files in your browser. Neither file is ever uploaded to a server.
What happens when the two CSV files have different columns?
Rawsort aligns columns by header name automatically. Missing values are left blank. No data gets misaligned.
Can I merge more than two CSV files?
Rawsort merges two files at a time. For more, merge two first, download the result, then merge that with the next file.
Is the CSV Merger free to use?
Yes, completely free. No account, no paywall, no usage limits.