File Extensions for Adobe InDesignby M.A. Helt
Adobe InDesign, the page-layout software in Adobe Creative Suite, supports several different file formats for saving and exporting documents. Choosing the right file format is essential, especially when transferring documents between different versions of InDesign, to avoid problems later. In addition to the various native InDesign file formats, the software also has several different export options to assist with distribution of content.
INDD: InDesign Document
The INDD file extension is the default file type for saving documents created with InDesign. Users save documents in this format by selecting the "Save As" feature under the "File" menu and choosing Document from the "Format" drop-down menu.
INDT File Extension: InDesign Template
The INDT file extension is used when a template is created with InDesign. Users save documents in this format by selecting the "Save As" feature under the File Menu and choosing "Template" from the "Format" drop-down menu.
INX File Extension: Saving for Earlier Use
Adobe InDesign files can be opened only by the software version they were created in or by newer versions of the same software. For example, if you create a document in InDesign CS4 and need to send it to someone using CS3, you must first convert the document to an INX formation. To do this, select "Export" from the "File" menu and choose ".INX" from the "Format" drop-down menu. The same process applies to saving a CS3 document for use with CS2.
IDML File Format: Saving CS5 Documents for Earlier Use
Saving CS5 documents for earlier use requires exporting the document to the IDML format, otherwise known as InDesign Markup Language. You can access this format by selecting "Export" from the "File" menu and choosing .idml from the "Format" drop-down menu. You can open the IDML file in CS4. If you need to open this document in CS3, you'll need to use CS4 software to export the INX file.
In addition to these InDesign readable file formats, the software can also export documents in a number of other formats. InDesign can export to PDF format for Adobe Acrobat, EPS format for Adobe Illustrator and other print-production software such as FlexiSign and JPG file format for images. All of these formats are accessible by selecting "Export" from the "File" menu and choosing the option from the "Format" drop-down menu.