What is XLSX?
XLSX is a modern spreadsheet format developed by Microsoft, serving as the default file type for Excel since Office 2007. It is based on the Open XML standard, where data is stored as compressed ZIP archives, reducing file size and enabling faster processing. XLSX files support spreadsheets, charts, graphs, complex mathematical formulas, and data analysis. Besides Microsoft Excel, XLSX files are compatible with Google Sheets, LibreOffice, and Apple Numbers.