TorDex – Search Tor Hidden Services
TorDex is a onion search engine build in the programming language called Rust. It implements a search algorithm like Google page rank, although not perfect it is one of the best search engines on Tor.
Fresh Onions is a simple onion site crawler that has the ability to search for Tor sites by title. They also have some helpful tools to find misconfigured onion sites and phishing pages.
not Evil – Search Tor
Not Evil is one of the oldest search engines on Tor. They don’t have any sponsors and run the site as not for profit.
OnionDir | Find Onion Sites & Reviews
Onion Dir isn’t exactly a search engine but rather a helpful directory of onion sites. Onion Dir moderates every submission and tried to keep the site free of spam.