Excel Data Deduplication
Identify and remove duplicates by full-row match or key columns. Preview highlights before you export.
Upload Excel File
Select the Excel file you want to deduplicate (.xlsx or .xls)
Supported: .xlsx, .xls
Excel Data Deduplication
Identify and remove duplicates by full-row match or key columns. Preview highlights before you export.
- Supported: .xlsx, .xls
- Local processing with privacy by design
- Millions of rows, instant
- Keep formulas & formats
Common use cases
How many duplicates are hiding in your CRM or accounting export?
Remove duplicate transactions
Bank exports sometimes include the same transaction twice if you re-pull a date range. Dedupe by date+amount+description to get a clean ledger.
Clean up customer lists
Multi-source customer imports collect duplicates. Dedupe by email or customer ID to get a single unified contact list.
Find duplicate timesheet entries
Dedupe a payroll-period timesheet by employee_id + date to catch double-punches before processing pay.
Best practices
Pick stable key columns
Choose columns that uniquely identify a record (e.g. email, order ID). Avoid columns prone to formatting drift like phone numbers.
Data security
Detection and export both run in your browser. No personally-identifiable information ever leaves your device.
Performance
Dedup is O(n) using a hash map. Even 500k+ rows complete in seconds; the bottleneck is usually the final download serialization.
Verify before deleting
Always review the "duplicate rows" download before discarding it — false positives happen if your key columns include timestamps that vary by millisecond.
Frequently Asked Questions
Full-row match vs. key-column match — which should I pick?
Use full-row match when any difference (even a stray space) means it's a different record. Use key-column match when records with identical IDs should be treated as duplicates regardless of other fields.
When duplicates are found, which row is kept?
You choose: keep the first occurrence (default) or the last. The other matching rows go to the duplicates output for review.
Can I download just the duplicates separately?
Yes. The tool produces two files in one pass: unique rows and duplicate rows. Useful for auditing — you keep the clean list and review what was removed.
Does case sensitivity matter?
String comparison is case-sensitive by default ("John" ≠ "john"). For case-insensitive dedup, pre-process the key column to lowercase using the Cleaner tool.