Spline is described as 'Browser-based tool for 3D modeling, animation, sculpting, and interactive experiences with real-time team collaboration, material editing, and physics simulation' and is a 3D Modeler in the photos & graphics category. There are more than 10 alternatives to Spline for a variety of platforms, including Web-based, Windows, Mac, Linux and SaaS apps. The best Spline alternative is Blender, which is both free and Open Source. Other great apps like Spline are SketchUp, Autodesk Maya, Autodesk 3ds Max and Cinema 4D.
Spline alternatives are mainly 3D Modelers, but if you're looking for
3D Animators or Graphic Design Tools you can filter on that. You can also filter by region, for example
EU-based alternatives if you prefer software developed in the European Union. These are just examples - use the filter bar below to find more specific alternatives to Spline.
Spline is specifically designed to put a WebGL scenes into websites. Maya is a desktop standalone 3D modeling software.