Clean CSV online: remove whitespace, empty rows and duplicates

Remove spaces, empty rows and exact duplicates in one click.

The CSV stays in your browser

Paste CSV

Need filters, mapping or dates?Continue in Data Transformer

Refine CSV locally by removing fully empty rows, surrounding spaces and duplicate records. Review the result in a table before downloading it.

How to use this tool

Paste CSV with headers and click Load preview.
Click Remove outer spaces, empty rows and duplicates. The tool runs these operations in that order and displays a summary.
Review the records in the table and download the cleaned CSV. Use Reset to return to the imported data.

Example input and result

After trimming whitespace, both Alice rows are identical. The tool keeps one and removes the fully empty row.

Input

name,email
 Alice Test , alice@example.com 
Alice Test,alice@example.com
Bob Test,bob@example.com
,

Result

name,email
Alice Test,alice@example.com
Bob Test,bob@example.com

Supported formats

Accepts CSV with automatically detected comma, semicolon or tab delimiters. The first row defines column names; quoted fields and line breaks inside cells are supported.

Downloads contain the cleaned dataset with headers and a comma delimiter. Use Data Transformer to export JSON or rename columns.

Limits and useful checks

Trims whitespace at the start and end of cells while keeping internal spaces. A row is removed as empty only when all its cells are empty after trimming.
Duplicates must match in every column. Similar names, different capitalization or records sharing an ID but differing in other values are not merged.
The preview displays up to 250 rows. Search and sorting change the view, while downloads contain the full cleaned dataset.

Frequently asked questions

Can I deduplicate by email alone?

This tool compares the entire row. To prepare a list of unique email addresses, select that column in Data Transformer and then apply deduplication.

Do I need to send my CSV to Seeft?

No. Cleaning and downloading run in your browser without an account.

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Limits and useful checks

Trims whitespace at the start and end of cells while keeping internal spaces. A row is removed as empty only when all its cells are empty after trimming.

Duplicates must match in every column. Similar names, different capitalization or records sharing an ID but differing in other values are not merged.

The preview displays up to 250 rows. Search and sorting change the view, while downloads contain the full cleaned dataset.