What is the default file extension of an Excel 2019 workbook?

This is the default file extension for a workbook created in Microsoft Excel 2019 and all versions of Excel starting from Excel 2007. The .xlsx format is based on the Office Open XML standard, which allows for better data management, smaller file sizes, and improved compatibility with other software.

The .xlsx file extension represents a standard Excel workbook that does not contain any macros. It is widely supported across modern systems and is considered more secure and efficient compared to older formats.