Join CSV Files by Column, free in your browser
Match rows from two CSV or TSV files by exact values in a shared column and combine each matching pair into one row.
How to join CSV files by a shared column
- Choose two CSV or TSV files with a shared column name.
- Select the column to match.
- Join the matching rows and download the result.
Limits & good to know
- Each file may be up to 50 MB and the combined total up to 200 MB.
- This is an inner join: unmatched rows and blank keys are omitted. Matching is exact and case-sensitive.
- Repeated keys create every matching row pair; output is limited to 500,000 rows.
Frequently asked questions
- Are my files uploaded to a server?
- Your files are processed on your device, not uploaded to our servers. Your file and edits are saved in this browser for recovery, and previous documents remain in Saved drafts when you open another file. Use Saved drafts to resume or delete individual copies, or clear this site’s browser data to remove all copies. Browser storage can be cleared or become unavailable; download important work.
- How is this different from Merge CSV Files?
- Merge appends records from multiple files. Join matches records by a shared value and combines columns from the matching rows.
- What happens when multiple rows have the same key?
- Every matching pair is included. If a key appears twice on both sides, it creates four result rows.
- Is this really free, or free "until you hit a limit"?
- Really free. Unlike most "free" PDF sites there is no task-per-day cap, no locked Pro features, no watermark stamped on your file, and no payment step before download. Every tool is the full tool.