Guide

How to remove duplicate rows from a CSV file

Decide what counts as a duplicate

A fully identical row is easy. In real lists, the same customer appears with different spacing or capital letters. Choose the columns that identify a record, such as email, or first name plus last name plus postcode.

Steps

Add the file, open Remove duplicates, tick the columns to compare, and choose whether upper and lower case should match. The first row of each group is kept. Surrounding spaces are ignored.

Keep a record of what was removed

Tick the option to save removed duplicates as a separate file. Check it before you delete the original, especially for mailing lists.

Compare on fewer columns with care

Matching on a single column such as last name will remove different people. Use the preview to check the result.

Works with Excel and JSON too

The same tool opens .xlsx and JSON files and can save the cleaned result in any of the formats.

Open the free CSV and Excel Toolkit

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