It’s interesting that there seem to be no tools available to check how Social Sharing Previews for Facebook, LinkedIn, Twitter work for a site that is not yet public. I can think of two solutions for this: simulating social network behavior and creating a page with stripped content but correct headers, which is opened to the public for a minute, then preview generation is performed through the actual tools of FB, LI, Twitter, conclusions are drawn on what to adjust, and the page disappears. The simulation could also be done, seems not too complicated.
