COMBINE / CSV + CSV

Merge CSV Files

Append rows from two CSV files into one. Columns match by name, even when their order differs. Your files stay in your browser.

How to merge two CSV files

Paste or open both files, then select Merge files. First-file rows come before second-file rows, with one header. This is a vertical append, not a SQL JOIN. Copy or download the merged CSV.

Input limits

Use UTF-8 CSV up to 5 MB per input, with non-empty, unique headers and consistent field counts. Blank rows are skipped. Output uses commas; formula-like cells gain a leading apostrophe for spreadsheet safety.

Merge CSV files example

First CSV

id,name
001,Alex
002,Sam

Second CSV

name,id,team
Jamie,003,Support
Taylor,004,Sales

Merged CSV: 2 + 2 = 4 data rows

id,name,team
001,Alex,
002,Sam,
003,Jamie,Support
004,Taylor,Sales

Frequently asked questions

Does this join records by an ID or remove duplicates?: No. It appends all rows from the first file, then all rows from the second. Duplicate rows and repeated IDs are retained; there is no key-based matching or SQL JOIN.
What happens when the column names or order differ?: Column names are trimmed and matched exactly, including case. First-file columns keep their order; new second-file columns are added at the end. Missing values become empty cells.
Can a file contain only headers?: Yes. Both files still need valid headers. Header-only files contribute columns and zero data rows. Counts exclude headers and blank lines; two header-only files produce a header-only result.