GlTF

Background
glTF™ (GL Transmission Format) is a royalty-free specification for the efficient transmission and loading of 3D scenes and models by applications. glTF minimizes both the size of 3D assets, and the runtime processing needed to unpack and use those assets. glTF defines an extensible, common publishing format for 3D content tools and services that streamlines authoring workflows and enables interoperable use of content across the industry.

Website: https://www.khronos.org/gltf/ Repo: https://github.com/KhronosGroup/glTF/blob/master/README.md

Importing
Currently not supported in FreeCAD v0.19

Exporting
FreeCAD has native export support for gITF format since v0.19.23074. Access this through the Std Export dialog.

Alternative export solutions
Previous to native glTF support there were a couple of workarounds:

1. Export as STEP → Import into CAD Assistant from Opencascade -> Export glTF

OR

2. Use the python library (website) by importing in to the FreeCAD Python console like so: import cqparts cqparts.Assembly.importer('step')('myfile.stp').exporter('gltf')('myfile.gltf')

Source: Forum thread

Related

 * Import Export
 * FreeCAD Howto Import Export