Find repeated records by email, customer ID or a combination of columns. Review what stays and what is removed before downloading either group.
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Choose a CSV file, paste data or try the sample. Nothing is uploaded.
What this tool does
Remove Duplicates from CSV
This duplicate remover compares complete CSV rows or the key columns you select. You can keep the first or last occurrence and optionally ignore case or surrounding whitespace when matching. Both output groups keep their original cell values and source order.
How to use it
Choose a CSV, TSV or TXT file, paste data, or try the built-in sample.
Confirm delimiter, encoding and whether the first record is a header before loading.
Select key columns or match whole rows; choose first or last occurrence and matching options.
Apply the rules, inspect both groups and download kept records or duplicates.
Common tasks
Remove repeated emails from a contact list without changing the remaining contact fields.
Find duplicate product records using a combination of SKU and region.
Download removed records separately to review the deduplication.
Privacy and local processing
Files and pasted text are processed on this device. The tool does not upload your data, change your original file, or fetch remote URLs. Download the result groups after reviewing the rules and preview.
Supported edge cases
Quoted commas, quoted newlines and leading-zero identifiers remain intact.
Records with an empty key are kept separately by default; you can explicitly include them in duplicate matching.
Blank physical lines are ignored, while records containing empty fields are preserved.
Malformed quotes, inconsistent column counts and duplicate or empty headers block processing.
Frequently asked questions
Can I remove duplicates based on one column?
Yes. Clear the key selection and choose a column such as email or customer ID. Choose several columns for a composite key.
Does it change the spelling or spaces in my data?
No. Case and whitespace settings affect matching only. Exported cells keep their source values.
Can I recover the removed records?
Your original file is unchanged. Download the duplicates group separately, or change the rules and apply them again to the original loaded records.
Are 00123 and 123 treated as duplicates?
No. Duplicate matching uses text values and does not convert identifiers to numbers.