local / CSV duplicate review / privacy-first
Review duplicate CSV keys and split rows.
Choose a key column to review duplicate groups, kept first rows, and duplicate rows before saving them separately.
Choose a CSV
Up to 5 MiB and 50,000 data rows. Reading, reviewing, and saving stay in this browser.
Choose a CSV file. It stays in this browser.
Duplicate review
| Key | Count | Source rows |
|---|
Boundaries
- The first row in each duplicate group is kept; later rows are listed as duplicates. The source is not changed.
- Blank keys are shown as a group. Confirm which row should remain before saving.
- There is no upload, external request, or automatic storage.