What join types are supported?

INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL OUTER JOIN — same as SQL.

Can I join on multiple columns?

Yes — add multiple key column pairs for composite key joins.

No. Everything runs locally in your browser.

Process files up to the browser memory limit.

Toggle case-insensitive matching to join regardless of case.

Perform SQL-style JOINs on two CSV files using a common key column. Fast, private, and secure browser-based tool with no sign

Your files never leave your device. Processed locally. 100% private.

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Complete your task perfectly in just three straightforward steps.

Upload the left and right CSV files to join.

Select key columns from each file and choose join type: INNER, LEFT, RIGHT, or FULL OUTER.

Download the joined CSV.

Everything you need to know about the CSV Joiner.

Continue working with our suite of free data utilities.

Filter CSV rows by conditions on any column. Supports AND/OR logic. The safest way to process sensitive data with zero-upload

Transform wide CSV tables to long format. Convert column headers into row values. Processed entirely in your browser for 100%

Sort CSV rows by one or more columns in ascending or descending order. Fast, private, and secure browser-based tool with no s