Duplicate Row Remover

Remove duplicate rows from CSV data by all columns or selected key columns, with case, whitespace and keep-first or keep-last options. Preview and download kept and removed rows.

Spreadsheet & Data Tools Runs client-side Free to use

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About the Duplicate Row Remover

Duplicate Row Remover finds rows that repeat in a CSV file and removes the extras. Compare whole rows or only the columns you choose — for example, email address alone.

Matching can ignore letter case and surrounding spaces, but the rows you keep are exported exactly as they were, in their original order. Keep the first or the last occurrence, see how many rows were kept and removed, preview both sets, and download the cleaned file and, if you like, the removed rows.

How to use

Upload or paste CSV data.
Compare by all columns or select key columns.
Choose case sensitivity, trimming and keep first or last.
Review the counts and preview kept and removed rows.
Download the cleaned CSV and optionally the removed rows.

Key features

Deduplicate by all columns or a selected combination.
Case-sensitive or case-insensitive matching.
Optional whitespace trimming for comparison only.
Keep first or keep last occurrence.
Input, kept and removed row counts.
Download cleaned rows and removed rows.

Best practices

Use key columns such as email or customer ID for contact lists.
Download the removed rows to review what was dropped.
Use keep last when later rows contain newer data.

Benefits

Clean mailing lists and exports quickly.
Original values and order are preserved.
Private: nothing is uploaded.

Frequently asked questions

Does trimming change my data?

No. Trimming and case options only affect how rows are compared; kept rows are exported exactly as they were.

Which row is kept with keep last?

The last occurrence of each duplicate group is kept, and kept rows stay in their original relative order.

How is this different from Remove Duplicate Lines?

Remove Duplicate Lines works on plain text lines. This tool understands CSV columns, quoting and multi-line cells, and can compare selected columns only.

Is my data uploaded?

No. Files and pasted data are processed only in your browser. Nothing is uploaded or stored, and the tool keeps working offline once the page has loaded.