Toolstack
100% Client-Side In-Browser Cleaning

Bulk CSV Data Cleaner

Clean, deduplicate, transform, and sanitize CSV spreadsheets in your browser. 100% client-side privacy.

Your Base64 data stays in your browser. Client-side only

Drop your CSV file here, or browse

Supports comma, semicolon, and tab delimiters, UTF-8 & BOM, and multiline cells. Zero server uploads.

Technical Guide: CSV Sanitization, Deduplication & Best Practices

1RFC 4180 Standard Compliance

Cells with delimiters or line breaks must be enclosed in double quotes. Quotes inside strings are escaped by doubling them ("") to preserve row alignment.

2UTF-8 BOM for Microsoft Excel

Excel often misinterprets standard UTF-8 files. Adding a Byte Order Mark (\uFEFF) forces Excel to render international characters and umlauts properly.

3CSV / DDE Formula Injection

Cells starting with =, +, -, or @ can trigger Dynamic Data Exchange (DDE) formula execution in Excel. The sanitizer automatically prepends an apostrophe to neutralize malicious formulas.

Frequently Asked Questions

Clear, concise answers to common questions about Base64 decoding, encoding, and specifications.

A Bulk CSV Data Cleaner is a browser-based utility that processes, sanitizes, and transforms CSV datasets. It removes duplicate rows, trims whitespace, fixes text casing, removes empty rows and columns, splits or merges columns, and cleans corrupted delimiters.