📊 CSV ↔ Excel XML Converter
Convert CSV to a minimal Excel 2003 XML Spreadsheet (SpreadsheetML) that Excel opens directly, or that format back to CSV. Nothing leaves your browser.
This is the plain-XML
.xml "SpreadsheetML" format Excel has been able to open since 2003 —
not the zipped .xlsx format, so no ZIP library is needed. Output has one
worksheet; numeric-looking cells are written with ss:Type="Number", everything else as
ss:Type="String". Special characters (& < > " ') are XML-escaped
both ways. Save the XML output with a .xml extension and Excel will open it as a workbook.