CSV to Excel

A genuine .xlsx file is a ZIP archive containing multiple structured XML parts (workbook, worksheet, styles, shared strings) per the Office Open XML spec — correctly building that from scratch needs a real spreadsheet-writing library, which this browser-only tool doesn't include. We'd rather point you to a reliable option than risk producing a corrupted file.

Excel and Google Sheets can both open a .csv file directly (File > Open, or just double-click it if Excel is your default CSV handler) — once open, use "Save As" (Excel) or "Download > Microsoft Excel" (Google Sheets) to get a real .xlsx file with your data already in cells.

As a quick reference pointing you to the simplest reliable path, rather than a fake converter that might produce a broken file.