As the name suggests, Open 3D Model Viewer is a dedicated free and open-source 3D file viewer for Windows 11/10. In it, you can visualize 3D models of formats including 3DS, OBJ, PLY, DAE, STL, etc.

The native 3D apps like 3D Viewer or Paint 3D don’t let you open a STEP file. So, you will have to use a third-party tool that allows you to open an STP file.

🔧 Web-based 3D STEP file flattener with dimensional accuracy. Interactive Three.js viewer, advanced surface flattening algorithms (conformal/energy/hybrid), and multi-format export (SVG/DXF/PDF). B ...