Remove Duplicate Rows from CSV Files Online
Remove duplicate rows from CSV files based on all columns or a selected subset of key columns.
Frequently Asked Questions
Yes. Select "Selected key columns" and check the columns you want to use as the duplicate key. For example, to remove rows with the same email address regardless of other differences, check only the Email column.
You can choose. By default the first occurrence is kept. Switch to "Last occurrence" if you want to keep the most recently added record.
Two rows are duplicates when all selected key column values match exactly, including case and whitespace. "John Smith" and "john smith" are treated as different values. Use consistent formatting in your data before deduplication if case-insensitive matching is needed.
The tool handles files up to 500 MB. For very large files, performance depends on server memory. If processing times out, split the file into chunks using the CSV Splitter first, deduplicate each chunk, then merge the results.
No. Rows are kept in their original order. Only duplicate rows are removed.
Related Tools
-
CSV Repair ToolAutomatically detect and fix common CSV formatting errors in…
-
CSV Encoding DetectorDetect the character encoding of any CSV file — UTF-8, UTF-1…
-
CSV Delimiter ConverterConvert CSV files between delimiters — comma, semicolon, tab…
-
CSV ValidatorValidate your CSV file for structure errors, encoding issues…
Your Privacy
Files uploaded for server processing are stored in a secure temporary location, processed immediately, and deleted automatically. We do not read, store, or share your data.