The most reliable way to "downsave" an InDesign file for any version from is to export it as an InDesign Markup Language (IDML) file. Open the file in the newer version of InDesign. Go to File > Export (or use the shortcut Cmd/Ctrl + E ). In the format dropdown menu, select InDesign Markup (IDML) .
: Once opened in the older version, go to File > Save As to convert it back into a standard .indd document specific to that version. Method 2: Automatic Conversion (Creative Cloud) how to convert indesign file to older version
If you are a Creative Cloud subscriber, Adobe offers a "Simple Saveback" service. The most reliable way to "downsave" an InDesign
. You can now open this .idml file in any older version of InDesign (CS4 or later). how to convert indesign file to older version