FAQ

Common questions about CSV Join.

What is a join key?

A join key is the column shared by both CSV files, such as id or email. Rows with matching key values are combined into one row in the output.

Do I need to install Pandas or Python?

No. This tool performs the merge directly in your browser, so you can join CSV files without writing any code.

Is my data uploaded to a server?

No. All processing happens locally in your browser. Your CSV data is never sent to or stored on our servers.

What happens if a key exists in only one file?

Only matching rows are combined by default. Rows without a match in the other file are left out of the joined result.

Can I join files with different column names?

Yes, as long as both files contain the join key column. Other columns can have different names and will appear in the merged output.