CSV Deduplicator

Remove duplicate rows from CSV — works entirely in your browser

Input CSV

Deduplicated Output

Click "Remove Duplicates" to see output

About the CSV Duplicate Remover

This tool removes duplicate CSV rows either by matching a single key column, such as email, or by comparing entire rows. It reports how many duplicates were dropped so you can sanity-check the result before importing.

Remove duplicate CSV rows before an import, because most systems reject the whole file on a unique-constraint violation rather than skipping the offending row. Merged mailing lists, combined exports and repeated form submissions all produce duplicates.

Two matching modes cover the real cases. Key-column mode deduplicates on one field — the usual choice for email or customer ID, where two rows are the same person even if a phone number differs. Whole-row mode only drops rows that are identical in every field, which is the safe option when you are not sure which column is authoritative.

The count of removed rows is reported, so you can tell the difference between a file that had a few repeats and one where a merge went badly wrong. It all runs in your browser.

How to use the CSV Duplicate Remover

  1. Upload your CSV. Provide the file containing duplicate rows.
  2. Choose the matching mode. Deduplicate on one key column, or require entire rows to match.
  3. Pick the key column. For key mode, choose the field that identifies a record, such as email.
  4. Download the clean CSV. Review how many rows were removed, then save the deduplicated file.

CSV Duplicate Remover features

  • Duplicate detection
  • Preview before removal
  • Count display
  • File upload support
  • Instant processing
  • Download cleaned CSV

Frequently asked questions

Should I match on a key column or the whole row?

Use a key column such as email when two rows mean the same record. Use whole-row matching when only identical rows should be dropped.

Which duplicate is kept?

The first occurrence is kept and later matches are removed, so the original order is preserved.

Does it tell me how many rows were removed?

Yes. The count of dropped rows is reported so you can sanity-check the result before importing.

Is matching case sensitive?

Key matching ignores case and surrounding spaces, so [email protected] and [email protected] count as the same record.

Is my file uploaded?

No. Deduplication happens entirely in your browser.