Shodan is the world's first search engine for Internet-connected devices. ... Use Shodan to discover which of your devices are connected to the Internet.
Shodan is a search engine that lets the user find specific types of computers (routers, servers, etc.) connected to the internet using a variety of filters. Some have also described it as a search engine of service banners, which are meta-data the server sends back to the client. This can be information about the server software, what options the service supports, a welcome message or anything else that the client can find out before interacting with the server.
IOT search engine: