Convert Excel to CSV without uploading your spreadsheet
Import tools, scripts, and databases often need CSV rather than .xlsx. This page reads an Excel workbook in the browser and writes a CSV for each sheet, using the tab name as the filename. A single-sheet workbook produces one CSV. SheetJS parses the workbook on your device, so payroll, budgets, customer lists, and other confidential business data are not uploaded.
How it works
- Drop an .xlsx or .xls file below, or several at once.
- Each worksheet is read and converted to CSV on your device.
- Download one CSV per sheet, named after the worksheet.
Frequently asked questions
What happens with multiple worksheets?
Each sheet becomes its own CSV file, named after the tab (for example Budget and Forecast). A workbook with a single sheet produces a single CSV named after the file. CSV has no concept of multiple sheets, so splitting them is the only faithful option.
Are formulas exported, or their results?
The calculated values are exported. The CSV contains what the cells display, not the formula text. That is almost always what you want when moving data into another tool. If you need the formulas themselves, keep the Excel file.
Is my spreadsheet uploaded to convert it?
No. SheetJS runs as JavaScript in your browser, so the workbook is read and converted entirely in local memory. Financial models and personnel data never leave your machine, and conversion works offline once the page has loaded.
Do .xls (older Excel) files work too?
Yes. Both the modern .xlsx format and the legacy binary .xls format are supported. Charts, images, and cell formatting are dropped. CSV is plain tabular text, but the cell values come through.