Should I use XLS or XLSX?

What is the best format to save an Excel file?

Most of the time you use the XLSX format: It's save (can't store malicious code), has the maximum number of rows and columns and is best known. XLSX is available since Excel 2007 and replaces the old XLS file type.

What is the difference between an XLS file and an XLSX file?

The File Format Difference Data is arranged in an XLS file as binary streams in the form of a compound file as described in [MS-XLS]. In contrast, an XLSX file is based on Office Open XML format that stores data in compressed XML files in ZIP format.

What file type should Excel be?

Excel File extensionExcel File format.xlsxExcel workbook.xlsmExcel macro-enabled workbook.xlsbExcel binary workbook.xltxExcel template

When did Excel change from XLS to XLSX?

XLS vs XLSX In the Microsoft Office 2007 release, Microsoft decided to change the default file format to a different format and adding and additional x for all their document extensions; for Excel, this ended up as XLSX.