Remove duplicate rows from a CSV file
Last reviewed 2026-09-19
Duplicates usually come from merging exports, repeated imports or systems that write the same record twice. Whether two rows count as duplicates depends on your data: sometimes the whole row must match, sometimes only an ID or an email address.
Messages you might see
- “Duplicate rows in an exported CSV”
- “Same customer or transaction appears more than once”
Why it happens
- Several exports were combined and overlap.
- The same import was run twice.
- A source system exports the same record once per related item.
Try this first (free, no tool needed)
- In Excel select the data and use Data > Remove Duplicates, choosing which columns must match.
- In Google Sheets use Data > Data cleanup > Remove duplicates.
- Decide before you start whether to keep the first or the last occurrence, because the rows can differ in other columns.
If that didn't work
These tools run in your browser. Your file is read and repaired on your own device and is never uploaded.
Duplicate Row Remover
Finds exact duplicates or duplicates by chosen key columns (optionally ignoring case), keeps the first or last occurrence, preserves the original order and delimiter, and shows how many rows were removed before you download.
Open Duplicate Row RemoverCommon questions
Does it change the rest of the file?
No. Order and delimiter are preserved and only the rows you approve are removed.
Is my file uploaded anywhere?
No. The tool runs as a program inside your own browser, so the file is read and repaired on your device and never sent to a server.