Remove duplicate rows
Remove Duplicate Rows from a CSV
Detect duplicates using all columns or selected columns and keep the first matching row. Your CSV never leaves your browser.
CSV processing stays in your browser
Your files are not uploaded to a server.
File selection
Choose 1 CSV file up to 50 MiB. Its name and contents are never sent outside your browser.
Drag and drop a CSV file here
1 CSV file, up to 50 MiB
Import settings
Auto-detection covers only UTF-8 and Shift_JIS. For CSV files from mainland China, Korea, Taiwan, or Western Europe, select the matching encoding manually.
How it works
Keep one row for each email address
How it works
Keep one row for each email address
Compare email addresses and keep only the first matching row.
Input example
| Name | |
|---|---|
| [email protected] | Alice Smith |
| [email protected] | Alice Smith (updated) |
Output example
| Name | |
|---|---|
| [email protected] | Alice Smith |
The first row is kept, and the number of removed duplicates is shown.
Remove duplicate CSV rows
Compare all or selected columns, keep the first row, and exclude later matches.
Features
- Detect duplicates across all columns or multiple selected keys.
- Check that the input row count matches the excluded and output rows.
How it works
- Choose a CSV and review the key columns.
- Compare all columns or selected columns.
- Run, then review excluded rows and the preview.
Before you start
- Case can be ignored, but surrounding spaces and full-width forms remain distinct.
- The first row is kept. Sort first to keep the newest or highest-priority row.
View FAQs for this tool
Related tools
Sort first to choose the kept row, then summarize the cleaned data.