3Dfiretypetransform
This is a program that converts an entire folder of 3D files to a specified 3D format.
There are three versions in the file, Blender 2.8 / Blender 2.79 English version, Blender 2.8 Chinese version, mainly because Blender 2.79 version has a very common format "3DS", if you need to convert to .3ds format, then you can only use Blender 2.79x version.
This Addon can be converted to OBJ/FBX/GLTF/X3D (Blender 2.8x version or above), OBJ/FBX/3DS/X3D (Blender 2.79x version)
Install
2.8x up. Edit -> Preferences -> Addon -> Install
2.79x. File -> User Preferences -> Addon -> Install Add-on from File