Office 2007 File Format MIME Types for HTTP Content Streaming

Summary

Office 2007 introduced new file formats for common document types (Word documents, Excel spreadsheets, and PowerPoint presentations), and has standardized on new MIME types for each new format.  The following information is provided to document the new MIME types and their proper use in HTTP content streaming situations.

More Information

The following table documents the HTTP MIME types that are available when working with Office 2007 documents:

Ext	MIME Type
.doc	application/msword
.dot	application/msword
.docx	application/vnd.openxmlformats-officedocument.wordprocessingml.document
.dotx	application/vnd.openxmlformats-officedocument.wordprocessingml.template
.docm	application/vnd.ms-word.document.macroEnabled.12
.dotm	application/vnd.ms-word.template.macroEnabled.12
.xls	application/vnd.ms-excel
.xlt	application/vnd.ms-excel
.xla	application/vnd.ms-excel
.xlsx	application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
.xltx	application/vnd.openxmlformats-officedocument.spreadsheetml.template
.xlsm	application/vnd.ms-excel.sheet.macroEnabled.12
.xltm	application/vnd.ms-excel.template.macroEnabled.12
.xlam	application/vnd.ms-excel.addin.macroEnabled.12
.xlsb	application/vnd.ms-excel.sheet.binary.macroEnabled.12
.ppt	application/vnd.ms-powerpoint
.pot	application/vnd.ms-powerpoint
.pps	application/vnd.ms-powerpoint
.ppa	application/vnd.ms-powerpoint
.pptx	application/vnd.openxmlformats-officedocument.presentationml.presentation
.potx	application/vnd.openxmlformats-officedocument.presentationml.template
.ppsx	application/vnd.openxmlformats-officedocument.presentationml.slideshow
.ppam	application/vnd.ms-powerpoint.addin.macroEnabled.12
.pptm	application/vnd.ms-powerpoint.presentation.macroEnabled.12
.potm	application/vnd.ms-powerpoint.presentation.macroEnabled.12
.ppsm	application/vnd.ms-powerpoint.slideshow.macroEnabled.12

To fully support the new types, web server administrators are advised to add the MIME types for the Open XML formats to their web server metabase settings so as to add the correct MIME type header in documents saved directly on the server and sent back.  For Windows 2003 Servers running IIS 6.0, you can add the Open XML types in IIS Manager, Server Properties, MIME Types.  These new formats are included in Windows 2008 running IIS 7.0 by default.  For more details on the default MIME types for IIS, please see the following KB article:

936496: Description of the default settings for the MimeMap property and for the ScriptMaps property in IIS

Clients that install Office 2007 or the Office 2007 File Format Compatibility Pack will get client-side MIME mappings to these formats by default.  

To use the MIME type in your ASP/ASP.NET code, you should use the built-in Response.ContentType property and set it to the MIME value that matches the content type you are providing.  If you fail to set the correct type, security checks by the client may prevent the content from being opened or may prompt the user with an alert that the file is not in the correct format.

Comments

• Anonymous
  May 08, 2008
  Web sites that use an XLS MIME type to open content in Excel 2007 from a web site may see warning alert that file is in a different format than its extension. This is a new alert to Excel 2007. The reason for the alert, and things you can do to work around

• Anonymous
  May 08, 2008
  The following post offers documentation on the Office 2007 MIME Types that can be used for HTTP content

• Anonymous
  April 30, 2009
  ReturnPath: Received: by 10.100.105.15 with SMTP id d15mr3505060anc.140.1241107989947; Thu, 30 Apr 2009 09:13:09 0700 (PDT) Date: Thu, 30 Apr 2009 12:13:09 0400 From: Bill Branan <bbranan@fedora...