neatcsv

neatcsv is a browser-based data cleaning tool for CSV, Excel (.xlsx/.xls) and JSON files.

All processing happens locally in your browser — your data is never uploaded to any server. This makes neatcsv fully GDPR compliant and safe for sensitive datasets like customer lists, financial records, or HR exports.

Key features:

• Remove duplicates (by single or multiple columns, case-insensitive)
• Validate and clean email addresses
• Normalize mixed date formats to a standard format
• Format numbers and currencies
• Trim whitespace and remove special characters
• Convert CSV ? Excel ? JSON
• Validate CSV file structure

Plans start at €9/month for 10,000 rows. A free trial is available without registration.

Great alternative to: OpenRefine, Excel macros, Google Sheets scripts, Trifacta, or manual Python/pandas scripts.