3D Viewer Online is described as 'View, Measure, Share and Embed 3D models and 2D drawings directly in your browser. No installation required, works on computers, smartphones and tablets. Files supported : STP, IGS, STL, PLY, OBJ with MTL, DXF' and is a 3D Modeler in the photos & graphics category. There are more than 10 alternatives to 3D Viewer Online, not only websites but also apps for a variety of platforms, including Windows, Android, Linux and Mac apps. The best 3D Viewer Online alternative is SculptView, which is both free and Open Source. Other great sites and apps similar to 3D Viewer Online are 3D House Planner, STP Viewer, A360 VIEWER and Online 3D Viewer.