CSV ↔ Excel Converter

CSV ↔ Excel Converter turns CSV data into an Excel .xlsx workbook and exports any worksheet of an .xlsx file as CSV. It detects the delimiter and header row, shows a table preview, and handles Unicode, quoted fields, embedded commas and line breaks. Files are read and written in your browser without uploading.

CSV is the common exchange format for data, while Excel is where people sort, filter and share it. Opening CSV directly in Excel can split columns incorrectly or drop leading zeros. Converting with a preview lets you check the result first and keep values intact.

1. Choose CSV → Excel or Excel → CSV.
2. For CSV → Excel, upload a CSV file or paste CSV text.
3. Check the detected delimiter and header row, and change them if needed.
4. Review the table preview and any notes about the data.
5. Press Download .xlsx to save the workbook.
6. For Excel → CSV, upload an .xlsx file, choose a worksheet and delimiter, then press Download CSV.

• Two-way CSV and .xlsx conversion
• Delimiter auto-detection for comma, semicolon, tab and pipe, with manual override
• Header row detection with manual override
• Quoted fields, embedded line breaks and Unicode preserved
• Leading zeros and long digit strings kept as text
• Worksheet selection and table preview
• Optional UTF-8 BOM for Excel-friendly CSV
• Clear messages for empty, corrupt, encrypted and unsupported files

• Check the preview before downloading, especially the delimiter and header choice.
• Keep the UTF-8 BOM option on if the CSV will be opened in Excel.
• Use semicolon output for regions where Excel expects semicolons.
• Recalculate and save workbooks in Excel before converting if formulas matter.
• Export each worksheet separately when a workbook has several sheets.