CSV ↔ Excel Converter
Convert between CSV and Excel (.xlsx) files, right in your browser.
About this tool
Convert CSV text into a real Excel (.xlsx) file, or pull the first sheet of an Excel workbook back out as CSV — using the open-source SheetJS library, entirely in your browser. Nothing is uploaded anywhere.
Frequently asked questions
- Does "Excel → CSV" handle multiple sheets?
- No — only the first sheet in the workbook is converted. For a multi-sheet file, open it in a spreadsheet app and export the specific sheet you need, or split it into separate files first.
- How are number and date formats handled?
- Values come through as their underlying data — numbers as plain numbers and dates as spreadsheet date values — which may look different from a custom cell format (like currency symbols) applied in the original spreadsheet.
- Are my files uploaded anywhere?
- No — all conversion happens entirely on your device. Nothing is sent to any server.