How to Use — Step by Step
1
Upload your file
Any CSV, XLS or XLSX file.
2
Choose group columns
All columns (default) or selected columns only.
3
Click Deduplicate
Rows are grouped; a count badge appears on each group.
4
Filter results
View All · Duplicates only · Unique only.
5
Download
CSV with __count column showing occurrences per group.
Features
Flexible grouping
All columns or selected columns.
Count badge
See how many copies existed (e.g. 3×).
3 filter modes
All, Duplicates, Unique.
Original order
First occurrence keeps its row position.
Blank-cell safe
Empty cells treated as a distinct value.
100% in-browser
Your data never leaves your device.
Export
Download format: Output: CSV with __count column appended.
Privacy & Security
Your files never leave your device. All processing happens entirely inside your browser tab using JavaScript.
No data is uploaded to any server, no account is required, and nothing is stored after you close the tab.
Fully GDPR-friendly — no data processing obligations are created by using this tool.