XLSX to XLSConvertisseur — Rapide et Gratuit

XLSX is a spreadsheet format: it stores cell values, formulas, formatting, and charts as zipped XML, the default format for Microsoft Excel 2007 and later. XLS is a spreadsheet format that stores data in the XLS format. This conversion changes the file's encoding, compression method, and supported feature set. Cell values and structure are preserved; formulas are evaluated to their computed values in plain-text target formats. Converting between these two formats is common when the source application does not support XLS natively or when the target platform only accepts XLS. 1converter processes this conversion server-side using open-source tools. Files are transferred over HTTPS, converted on secure cloud servers, and automatically deleted after 24 hours.