Definition: Office file formats

Starting with Office 2007, Microsoft switched to Office Open XML (OOXML) as the default file formats for its applications. However, the legacy .doc (Word), .xls (Excel) and .ppt (PowerPoint) file formats are still supported in Office and widely used for compatibility with documents created in versions of Office from Office 97 to Office 2003. The older, legacy formats are used worldwide and are expected to remain popular for years. For more details on the new formats summarized below, see Office Open XML.

   OFFICE OPEN XML (OOXML)
   DEFAULT FILE EXTENSIONS
   (As of Office 2007)

   WORD

  .docx   Document
  .docm   Macro
  .dotx   Template
  .dotm   Template and macro


   EXCEL

  .xlsx   Worksheet
  .xlsb   Fast binary worksheet
  .xlsm   Macro
  .xltx   Template
  .xltm   Template and macro
  .xlam   Add-in and macro


   POWERPOINT

  .pptx   Presentation
  .pptm   Macro
  .potx   Template
  .potm   Template and macro
  .ppam   Add-in
  .ppsx   Slide show
  .ppsm   Slide show and macro