Convert Excel (XLSX) to CSV Online Free

Need your Excel data as plain CSV? AllConvert converts XLSX to CSV instantly, right in your browser. No upload, no account, no Microsoft Office required.

Why convert XLSX to CSV?

CSV is the universal language of data: import tools, databases, CRMs, scripts in Python or R, and almost every web service that accepts a data upload expects CSV, not Excel workbooks. Converting XLSX to CSV strips away formatting, formulas and macros, leaving just the clean rows and columns of values that data tools want.

What happens during the conversion?

AllConvert parses the workbook in your browser and writes the first sheet out as standard comma-separated values, quoting fields where needed. Formulas are exported as their calculated values. If your workbook has multiple sheets, move the one you need to the first position before converting.

Sensitive spreadsheets stay private

Spreadsheets often contain customer lists, financials or HR data. Because AllConvert runs entirely in your browser, the file is never uploaded to any server — there is nothing to trust, because nothing leaves your machine. Need JSON instead? Try XLSX to JSON.

How to convert

1. Open AllConvert and drop your XLSX file onto the page.
2. Select CSV from the format dropdown on the file card.
3. Click Convert and download your result.

The entire process runs locally in your browser. Nothing is uploaded, and it works on desktop and mobile, in Chrome, Firefox, Safari, and Edge.