3D-Coat is a complete 3D modeling, sculpting, and texturing program.
You can upload to Sketchfab directly from the application with full support for PBR workflows.
When your 3D-Coat model is ready to upload, go to Help > Upload Mesh to sketchfab.com.
3D-Coat will prepare your model files and then open a tab in your default browser. Enter a model title, description, tags, and your Sketchfab API Token. Finally, click the Upload to Sketchfab button.
When the upload finishes, you'll be redirected to another preview page to wait for processing to finish. Then you can edit your 3D Settings in Sketchfab and start sharing!