CSV to XLSX Converter

Convert CSV to Excel without breaking leading zeros, IDs, or dates. Control column types to preserve data integrity.

How to Use

Drop a CSV file onto the upload area or click to browse
Choose data handling options: preserve text columns, parse dates, etc.
Optionally customize sheet name, encoding, and delimiter settings
Click "Convert to .xlsx" to generate your Excel file
Download the converted file with preserved data integrity

Note: All processing happens locally in your browser. No files are uploaded.

How it Preserves Your Data

Leading zeros (e.g., zip codes, product IDs) are written as text with Excel's text number format.
Long numbers (>15 digits) are kept as text so Excel doesn't turn them into scientific notation.
Dates only parse when you allow it. Otherwise, they're plain text.