Converter
Excel ↔ CSV Converter — Large Workbooks in Your Browser100% Private and Secure
- Convert
- Mobile Friendly
- Accessibility Tested
- SEO Optimized
- Fast Loading
- Responsive
Version 1.0.0 · Last reviewed
How it worksShow guide
Introduction
Drop an .xls or .xlsx workbook and flatten a sheet into CSV, or paste CSV and download a new Excel file. Sheets are listed so you can pick which tab to export. Conversion is chunked so large catalogs stay on this device.
Step-by-step
- Choose Excel → CSV or CSV → Excel
- Drop a workbook or paste CSV, then pick the sheet and delimiter
- Convert, preview rows, then copy or download
Worked example
CSV → Excel writes Sheet1 with two columns. Switching to Excel → CSV reads that sheet back to id,name / 1,Ada.
Use cases
- Turn a multi-megabyte product spreadsheet into CSV
- Rebuild an .xlsx from a CSV export without Excel
- Preview the first rows before downloading the full file
Frequently asked questions
Does my spreadsheet leave the browser?
No. Unzipping and conversion run locally. Download uses a blob in this tab.
Can I convert a huge .xlsx?
Yes — up to 32 MB and 100,000 rows. Preview shows the first rows; download the CSV for the rest. Work happens in chunks so the tab can keep painting.
What about old .xls files?
Yes. Excel 97-2003 (.xls) workbooks are read in the browser alongside .xlsx, .xlsm, and Excel 2003 XML. CSV export still rebuilds a modern .xlsx download.
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