CSV Duplicate Row Remover
Remove duplicate rows from your CSV. Deduplicate by all columns or choose specific key columns. See exactly how many rows were removed.
Select the column(s) to use as deduplication keys (rows with matching values in these columns will be deduplicated):
About CSV Duplicate Row Remover
The CSV Duplicate Row Remover finds and removes duplicate rows from your CSV data. You can deduplicate by exact full-row match, or choose specific key columns - useful for deduplicating by email address, ID, or any other unique identifier while keeping other column differences.
Deduplication Modes
- All columns - Two rows are duplicates only if every single cell matches exactly. Use this for a clean full-row dedup.
- Specific key columns - Two rows are duplicates if the selected key columns match. The first occurrence is kept; subsequent duplicates are removed.
How to Use
- Upload a CSV file or paste CSV text.
- Optionally choose which columns to use for duplicate detection (default: all columns).
- Click Remove Duplicates - the deduplicated CSV appears in the output.
- The tool shows how many duplicate rows were removed.
- Download or copy the cleaned CSV.
How It Works
Each row is converted to a string key using the selected columns' values. A Set tracks seen keys - if a key has already been seen, that row is considered a duplicate and excluded from the output. Only the first occurrence of each key is kept.
Example
A user export with duplicate emails: upload the CSV, select the Email column for duplicate detection. The tool removes any rows where the same email appears more than once, keeping only the first occurrence.