Remove Duplicate CSV Rows

Remove duplicated items from a CSV file by comparing full rows or selected columns. Keep first or last occurrence, preserve row order, ignore empty rows, and export a cleaned CSV directly in your browser.

Examples: , ; | (for tab, enter a real tab character)
No selected columns means duplicate detection is based on the entire row.

⭐ Remove Duplicate CSV Rows - Explanation & Examples

The Remove Duplicate CSV Rows tool helps you remove duplicated items from a CSV file while preserving CSV structure, column order, and row order. By default, duplicate detection uses the entire row and keeps the first occurrence.

⭐ What this CSV duplicate remover does

  • Validates CSV input and parses it with your selected delimiter
  • Removes duplicate rows using full-row comparison by default
  • Lets you detect duplicates by one or more selected columns
  • Ignores completely empty rows automatically
  • Returns a valid cleaned CSV output

⚙️ Duplicate detection options

  • Select column(s): choose one or more columns for duplicate detection. If none is selected, the full row is used.
  • Has header row: treats the first row as headers and excludes it from duplicate processing.
  • Case-insensitive mode: compares values without case differences.
  • Trim whitespace: ignores leading and trailing spaces during comparison.
  • Custom delimiter: supports comma, semicolon, pipe, tab, or another single-character delimiter.
  • Keep last occurrence: keeps the last matching row and removes earlier duplicates.

🔎 How duplicate removal works

  1. Paste CSV data or upload a CSV file.
  2. Set delimiter and header mode.
  3. Optionally detect and select one or more duplicate-check columns.
  4. Choose keep first (default) or keep last occurrence.
  5. Generate the cleaned CSV, then copy or download it.

🔎 Example

Input CSV:

name,email
John,john@example.com
Jane,jane@example.com
John,john@example.com
Bob,bob@example.com
Jane,jane@example.com

Output (default, keep first):

name,email
John,john@example.com
Jane,jane@example.com
Bob,bob@example.com

Output (keep last occurrence enabled):

name,email
John,john@example.com
Bob,bob@example.com
Jane,jane@example.com

⚠️ Notes

  • Rows remain in their original order after duplicate filtering.
  • When header mode is enabled, the first row is preserved as-is.
  • All processing happens locally in your browser for privacy.

Frequently Asked Questions

It removes duplicated rows from CSV data and returns a cleaned CSV output while preserving column order and row order.

By default, duplicates are detected using the entire row. The tool keeps the first occurrence and removes later duplicates.

Yes. You can select one or more columns. When columns are selected, only those columns are used to determine duplicates.

If no column is selected, the full row is used for duplicate detection.

When enabled, the first row is treated as column headers and is not processed as data. When disabled, all rows are processed as data.

It treats values with different letter casing as duplicates, such as "John" and "john".

It ignores leading and trailing spaces while comparing values, which helps detect duplicates with extra surrounding spaces.

Yes. You can enter a custom delimiter such as semicolon (;), pipe (|), or tab.

Yes. Enable Keep last occurrence to keep the last matching row and remove earlier duplicates.

Yes. Completely empty rows are ignored automatically during duplicate processing.

No. All CSV parsing and duplicate removal are done locally in your browser.