Convert Excel (XLSX or XLS) to CSV online — drop in a spreadsheet and get a clean, comma-separated file back in seconds.
Free for files up to 5 MB and 10,000 rows. Files are processed in your browser — nothing is uploaded to a server. No account required.
Drop in an .xlsx or .xls workbook and the first sheet comes back as CSV. Formulas are read at their calculated values, so what you see in Excel is what lands in the file — no #REF! or =SUM() leaking into your data.
Most systems that ask for a CSV upload will reject a workbook outright: billing importers, CRM bulk-loaders, database COPY commands, and almost every API that takes a file. This is the step between the spreadsheet someone emailed you and the format the tool on the other end will actually accept.
The conversion runs in your browser, which matters more here than usual — workbooks tend to carry payroll, pricing and customer lists. Nothing is uploaded. Every other tool on this site accepts spreadsheets too, so you can convert and then clean, dedupe or filter without a second upload.