Communities like r/Eaglercraft are the best places to find updated server lists. Players often post "Looking for group" threads or advertise new servers here.
When searching for "Eaglercraft 188 servers," you will generally find three categories of gameplay: eaglercraft 188 servers
As of this writing, these are the most active, reliable, and fun servers for the 1.8.8 version. Communities like r/Eaglercraft are the best places to