10 Search Engines to Explore the Invisible Web. Not everything on the web will show up in a list of search results on Google or Bing; there are lots of places that their web crawlers cannot access. To explore the invisible web, you need to use specialist search engines. Here are our top 12 services to perform a deep internet search. What Is the Invisible Web? Before we begin, let's establish what does the term "invisible web" refer to? The Deep Web. Home Page.