We were asked whether we have an invisible detector for Skype like we have the Yahoo detector, Hi5 and Facebook detector. For some time now, we have been doing research regarding such an invisible detector for Skype, but for now, the conclusion is that there is no such detector/scanner/checker under the form of a website. The good news is though that there are small tricks with which you can see if someone is invisible on Skype.
If the Yahoo detector is working invisibly and you can check someone without he or she finding out, with Skype you can’t do something like that. Probably the best known method is a very public one and very obvious. This implies sending a message to the person whom you’d wish to check. If on the right side of the message a small image appears with a circle that is almost closed and which is rotating like if it wants to load something, than the person is not logged in to Skype. If this takes approximately 3-5 seconds and then disappears that means that the person you are spying on is invisible on Skype.