MoxuTools

File tool

CSV Duplicate Remover

Drop in a CSV file and this tool finds the duplicate rows, shows you a few of them, and lets you download a copy without them. You choose which columns have to match, so you can treat two rows as the same when only their email address is identical, or only when everything is.

Your file is read and cleaned on your own device. It is never uploaded, and your original file is never changed.

Remove duplicates from your file

Stays on your device

How to use it

  1. Drop your CSV file onto the box, or click it to choose one.
  2. Tick the columns that decide whether two rows are the same. Leave them all ticked to compare whole rows.
  3. Check the summary and the examples of rows that will go. Change the options if they look wrong.
  4. Press the download button. You get a new file; the first row of each group is kept.

Which duplicate is kept?

The first row of each group is kept, and later matches are removed. The rows keep their original order, so nothing is re-sorted behind your back.

If you need the latest record instead (for example the newest order for each customer), sort the file so the newest rows come first, then remove duplicates.

Duplicates by one column or by the whole row

Comparing whole rows only removes rows that are identical in every column. That is the safe choice for exports that were accidentally pasted twice.

Comparing by one column, such as email address, order number or SKU, removes rows that share that value even if other columns differ. That is useful for mailing lists, but check the examples first, because the rows that are removed may hold slightly different details.

Why do some duplicates not get removed?

Computers compare text exactly. Ann, ann and Ann (with a trailing space) are three different values. That is why this tool has two options: ignore capital letters, and ignore spaces at the start and end. Spaces are ignored when comparing by default; the values in your saved file are not changed.

Different spellings, such as “St.” and “Street”, or typos, are not duplicates as far as a computer is concerned and need cleaning by hand.

Leading zeros, accents and Excel

Every value is kept exactly as text, so a code like 01234 stays 01234. The file is saved with a small marker (a UTF-8 BOM) so Excel shows accented letters correctly; untick it if another program complains. Excel workbooks (.xlsx) aren't read directly: in Excel choose File → Save As → CSV first.

Frequently asked questions

How do I remove duplicates from a CSV file?

Drop the file into the box above, choose which columns must match, and press download. You get a new CSV with the duplicate rows removed.

Will it change my original file?

No. The tool reads your file and builds a new one. Your original stays exactly as it was.

Is my file uploaded anywhere?

No. The file is processed by your browser on your own device. Nothing is sent to a server.

Does it keep leading zeros?

Yes. Every value is treated as text, so codes such as 01234 keep their zero. Opening the result in Excel may still drop leading zeros, so import it as text if that matters.

How big a file can I use?

Up to 25 MB in this free tool, which is many tens of thousands of rows. MoxuCSV Pro handles files up to 200 MB.

Can I remove duplicates in an Excel file?

Save the sheet as CSV first (File → Save As → CSV), use this tool, then open the result in Excel.

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Last reviewed 29 September 2026. Your files are processed by your browser and are never uploaded.