Free online FBX viewer

Drop a file and it renders instantly: drag to rotate, scroll to zoom, right-drag to pan, and toggle wireframe in the corner to see the triangle structure. Files that carry materials and textures, GLB and glTF, 3MF, 3DM, and colored PLY scans, render with them; the textures button switches back to the plain mesh. The panel below the viewer reports exact dimensions, volume, surface area, triangle count, and whether the mesh is watertight. Drop another file onto the viewer at any time to swap the model without reloading the page.

FBX is Autodesk's interchange format, used by Maya, 3ds Max, Blender, Unity, and Unreal. The viewer reads the mesh geometry and converts the file's own unit setting to millimeters; materials, rigs, and animation are ignored, so you see the bare model.