Managing and sharing 365 files

In this sample chapter from Microsoft Office Inside Out (Office 2021 and Microsoft 365), you will look at the file formats used in each of the Microsoft 365 applications and how to share them.

  • Understanding 365 file formats
  • Configuring save file options
  • Creating and managing files
  • Searching for 365 files
  • Protecting a 365 file
  • Preparing a file for sharing

The Microsoft 365 applications provide you with all the tools you need to create documents, presentations, workbooks, and publications. After you create your various files using the 365 applications, it is up to you to manage your files and share them with colleagues and coworkers.

In this chapter, we take a look at the 365 file formats used in each of the Microsoft 365 applications. We also look at your options for managing and sharing files.

Understanding 365 file formats

The default file formats for each of the 365 applications (excluding Outlook) take advantage of the open XML (eXtensible Markup Language) file standards. The file formats benefit file compression, improved damage recovery, better detection of files containing macros, and better compatibility with other vendor software.

Although some backward-compatibility issues may be involved when you attempt to share a file using one of these file formats with a user who still works with an earlier version of a particular 365 application (think pre-2010 versions), most problems have been ironed out. Users still working with earlier versions of the applications can take advantage of various conversion utilities and software updates that enable them to convert or directly open a file using one of the new file formats.

You can also save your files in file formats that offer backward compatibility for coworkers still using older versions of the Microsoft (formerly Office) suite applications. And the applications (such as Word and Excel) provide you with compatibility-checking tools that help negate any issues with files shared with users of legacy Microsoft applications.

As already mentioned, Word, Excel, and PowerPoint use the open XML file formats by default when you save a file in these applications. And you have some other file format options in these applications if needed.

Publisher, on the other hand, saves publications by default in the .pub file type. The .pub file type is “directly” compatible with versions from Publisher 2003 through Publisher 2013. Although Publisher does not enable you to save a publication in the open XML file format (like Word and Excel), you can save Publisher files in the XPS file type, which is an XML file format for “electronic paper.” Publisher also has file types available that you can use to make your publications backward compatible with collaborators who are using previous versions of Microsoft Publisher.

  • arrow.jpg For more about Publisher file types, see “Creating a new publication,” in Chapter 27.

The following lists provide an overview of some of the file types used in Word, Excel, and PowerPoint, respectively.


File Extension



XML file type; default file type for Word 2010, 2013, 2016, and 2019 documents


XML file type; macro-enabled document


XML file type; Word template


XML file type; macro-enabled Word template


Binary file type; document compatibility with Word 97–2003


Binary file type; template compatibility with Word 97–2003


File Extension



XML file type; default file type for Excel 2007, 2010, 2013, 2016, and 2019 workbooks


XML file type; macro-enabled workbook


XML file type; Excel template


XML file type; macro-enabled Excel template


Binary file type; document compatibility with Excel 97–2003


Binary file type; template compatibility with Excel 97–2003


File Extension



XML file type; default file type for PowerPoint 2007, 2010, 2013, 2016, and 2019 presentations


XML file type; macro-enabled presentation


XML file type; PowerPoint template


XML file type; macro-enabled PowerPoint template


XML file type; PowerPoint show


XML file type; macro-enabled PowerPoint show


Binary file type; presentation compatibility with PowerPoint 97–2003


Binary file type; template compatibility with PowerPoint 97–2003

The 365 applications also provide other file formats that make it simple for you to share your documents or workbooks in a format designed for easy viewing. A good example is the PDF file format (created by Adobe Systems), which allows users who have a PDF reader, such as the free Adobe Reader software installed on their computers, to view your files. Windows 10 also provides a PDF viewer (Windows Reader) to view a PDF document. The viewer enables you to search the PDF document using the Find tool.

The XML Paper Specification (XPS) file format also makes it easy for others to view your work. Windows 10 supplies an XPS viewer that enables any Windows 10 user to open and view files in the XPS file type. Figure 3-1 shows the Windows 10 XPS viewer containing a Word document converted to an XPS document.

Figure 3-1

Figure 3-1 A Word XPS document in the XPS viewer

Both the PDF and the XPS file formats are primarily designed to enable you to share a view of a particular file without requiring that the applications themselves be installed on the computer of the user who will view the file. Although both the PDF and XPS file types require a particular viewer type to view the file, viewers such as Acrobat Reader and some XPS viewers (including Microsoft’s XPS viewer) are available for free download on the web. Most operating systems, including Windows 10, have their own native PDF and XPS viewers.