By default, all software supports multiple file extensions. Office 365 supports at least 33 different file extensions. The basic files that Office 365 supports are .XLSX. However, not all of the extensions listed on the list are always used to save the effects of work in Office 365. Very often, files with such extensions are used as source data files used by Office 365.
Office 365 can be used to convert file formats between the file extensions listed below. You can open a file with one of the file extensions below via Office 365 and try to save it in another file format, also supported by Office 365.