Focused purpose
What this tool does
Remove exact or key-based duplicates from CSV or TSV locally. Preview the row-count impact, keep the first, last or most complete row, and download without an account.
- ✓ All-column or selected-key matching
- ✓ Case, whitespace and diacritic rules
- ✓ First, last or most-complete retention
- ✓ Row-count preview before removal
Workflow
How to use it
- 01
Open the file and select comparison columns.
- 02
Choose matching and retention rules, then preview the impact.
- 03
Confirm removal and export the deduplicated copy.
Available controls
Available options
- Compare every cell or selected business keys.
- Keep case-sensitive matching or relax it explicitly.
- Choose which occurrence survives.
- Review the before-and-after count before confirming.
Duplicate email rows
Example before and after
Two rows are exact duplicates.
Before
id,email 1,alex@example.com 1,alex@example.com 2,sam@example.com
After
id,email 1,alex@example.com 2,sam@example.com
Expected result: The first matching row is retained and one duplicate is removed.
Practical scenarios
Common use cases
Deduplicate mailing lists by email.
Keep the most complete customer record.
Remove repeated exports before merging.
HONEST LIMITS
Important limitations
- iSimilar spelling is not treated as a match.
- iDuplicate keys can represent legitimate repeated events; review groups first.
FAQ
Questions about this tool
What is an exact duplicate?
Every selected column has the same text value. Whitespace and case only differ if you normalize them first.
Can I deduplicate by email only?
Yes. Select email as the key and preview records that share it.
How does “most complete” work?
The row with the greatest number of non-empty selected fields is kept; ties remain deterministic.