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Runs in your browserRemove duplicate rows from a CSV
Merged mailing lists and repeated exports collect the same person twice. This removes the repeats, either where the whole row is identical or where one column matches, such as an email or an ID. The first one in the file is the one kept.
Your file stays on this computer. There’s no upload button here, because there’s nowhere to send it. This tool runs inside the page you opened — like a calculator on a web page, it keeps working once it has loaded. How this works, and how to check it →
How to use it
- Choose your CSV file.
- Name the column to match rows by, or leave it blank to match on the whole row.
- Click Remove duplicates. You'll be told how many rows were dropped.
Questions
Is my file uploaded anywhere?
No. The whole tool is inside this page, so the work happens on your computer. There is no server to send it to. If you'd rather check than take our word for it: use the tool once, on a sample file, with the settings you want. Then turn off your wi-fi and do exactly the same thing again in that tab, without reloading. It still works, because everything it needs is already here.
Which duplicate is kept?
The first one, in the order it appears in the file. Later matching rows are removed. If your file is sorted so the most recent record is last, sort it the other way before deduplicating.
Is matching case sensitive?
No, and space at the start or end of a cell is ignored too — so "[email protected] " and "[email protected]" count as the same. Turn on "Match capitals exactly" if you need them treated as different.