After converting the INDD file to PDF, you can open them and see them on web browsers, as well as PDF reader programs. These are the options you have to open an INDD file without InDesign on Windows.

This article shows you three ways that you can use to save an InDesign file from a higher version to a lower version so that it is compatible.

How to Open an INDD File With Photoshop. Though Photoshop doesn't directly open InDesign project files, the two programs are closely related.