Facebook has recently launched a feature to post 3D objects on the timeline. This is a boon to artists and creators who would like to design and publish their models. In the era of Augmented Reality, there are several apps that help in bringing 3D objects into the real world using smartphone's camera. Facebook has just started to allow 3D posts and thus they do support only glTF 2.0 formats currently. Maybe, we can expect a lot more 3D model formats in the future. A developer endpoint has also been developed to enable app developers to let users to post 3D objects.
Do you need to be a developer to post a 3D object on Facebook?
No. You can develop a 3D post on any tools such as Maya, 3D Max or online tools and you can export to glTF 2.0 format to post it on Facebook. The binary file of glTF 2.0 format will have a file extension ".glb" and a simple drag and drop of a ".glb" file will add the 3D object into your Facebook post.
How do I create a 3D object?
You can make use of any 3D modelling software in order to create a 3D object but makes sure that you can export to glTF 2.0 format. However, KhronosGroup has added some handful of 3D objects on GitHub and you can make use of it. Download the .glb file.
How to post 3D object on Facebook?
Drag and drop to Facebook status composer box, the website will start analysing the file to appear on the web page. Facebook restricts the file size of the 3D object. Please see that you do post not more thanĀ 3145728 bytes (3.14 MB). Facebook will not allow you to post the 3D object if it exceeds the maximum allowed size. 
Here is a 3D object that we posted on our page. Please visit our Facebook page for more such 3D models.
Share on our Facebook Page after you post a 3D object on your timeline.