CSV Cleaner & Normalizer
Clean messy CSV files, normalize headers, deduplicate rows, and fix encodings — all in your browser.
CSV Cleaner & Normalizer
Clean messy CSV files, normalize headers, deduplicate rows, and fix encodings — all in your browser.
How to clean CSV files online?
Clean and normalize your CSV files with our powerful data processing tool. Remove duplicates, fix encoding issues, normalize headers, and validate data integrity. Perfect for data migration, ETL processes, and database imports with enterprise-grade reliability.
Features
- Client-side CSV cleaning; privacy-first (no uploads)
- Header normalization, trimming, empty row/column removal
- Deduplication by keys, value normalization, dates and types
- Streaming parser handles large files (~50MB)
- Virtualized preview with Issues report export
- Export with custom delimiter, LF/CRLF, and encoding
How to use
- Drop or paste your CSV in the input area.
- Check delimiter, encoding, and whether the first row has headers.
- Toggle any operations you need under the Operations tab.
- Click Clean CSV to process in your browser.
- Review the Preview and Issues tabs; download the issues report if needed.
- Export the cleaned CSV with your preferred delimiter, line endings, and encoding.
Tips & Best Practices
- Always validate your data before processing to catch syntax errors early.
- Use the copy button to quickly transfer formatted output to your clipboard.
- For large files, consider breaking them into smaller chunks for better performance.
- Back up your original data before applying any transformations.
- Use keyboard shortcuts for faster workflow: Ctrl+A to select all, Ctrl+C to copy.
FAQ
Do you upload my CSV?
No. All processing happens locally in your browser; nothing is sent to a server.
How large can my file be?
Typically up to ~50MB on a modern laptop, thanks to streaming and a Web Worker. or external dependencies.
How are delimiter and encoding detected?
Delimiter is inferred from sample frequency/consistency; encoding uses BOM heuristics with UTF‑8 default. You can override both. The tool is engineered to handle both small and large inputs efficiently, leveraging modern browser capabilities for optimal performance.
Will the output work with Excel?
Yes. Choose CRLF line endings and Windows‑1252 or UTF‑8 as needed; you can also include headers.
Can it fix quotes and BOM?
Yes. It strips BOM and mitigates common quote issues via parsing and normalization.