Remove duplicate rows without losing control
Duplicate rows creep into CSV files constantly — merged exports, re-run reports, copy-paste accidents. This tool removes them with two strategies: entire row matches, where every field must be identical, or match on key column, where a single column such as email or ID defines uniqueness. In both modes the first occurrence wins and the original row order is preserved — nothing is sorted behind your back.
The part most dedupe tools skip: you can see exactly what was dropped. The removed rows appear in a collapsible panel below the stats, so you can verify the tool deleted what you expected before trusting the output — essential when the file is a customer list you cannot easily reconstruct. And because everything runs locally in your browser, that customer list is never uploaded anywhere.
How to deduplicate a CSV
- Paste your CSV — the delimiter is auto-detected, with an override if needed.
- Leave First row is a header ticked to keep the header out of the comparison.
- Pick whole-row or key-column matching, and turn off case sensitivity if Ada@example.com and ada@example.com should count as the same.
- Check the stats and the removed-rows list, then copy or download the result.
Cleaning up before or after deduplication
Deduplication often pairs with column cleanup: dropping the columns that make rows spuriously unique (timestamps, row IDs) before matching, or trimming a file down after. The CSV Column Extractor handles both — select just the columns you care about, then paste the result back here for a whole-row dedupe.