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CSVQuery

Find duplicate rows in a CSV file

Open your CSV file and see every row that appears more than once. Edit the query to check a single column such as email or ID.

Drop a CSV file here or click to choose one
Comma, semicolon, tab or pipe separated

How to find duplicates in a CSV file

The default query groups identical rows and keeps the ones that appear more than once. To check one column only, group by that column:

SELECT email, COUNT(*) AS n
FROM data
GROUP BY email
HAVING COUNT(*) > 1
ORDER BY n DESC

Compare total and unique values

SELECT COUNT(*) AS total,
       COUNT(DISTINCT email) AS unique_values
FROM data

If the two numbers differ, the column contains duplicates. Use the filter boxes under the result to look at a specific value, then download the rows you need.

Frequently asked questions

How do I find duplicates in one column?

Group by that column and keep groups with more than one row: SELECT col, COUNT(*) FROM data GROUP BY col HAVING COUNT(*) > 1.

Is the comparison case sensitive?

Yes, values must match exactly. Use UPPER(column) in the query to ignore case.

Does this change or upload my file?

No. Your file is only read in the browser and is never modified or sent anywhere.

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