The purpose of this website is to measure latency/packetloss between the client (you) and the server. The website does not actually detect packet loss due to the nature of this http connection using TCP. Though you will be able to see if some packets are delayed which usually means the packet was lost and resent. Check the measure latency box to switch to latency measure mode and display the latency of each ping along with the final total ave/max/min.