I'll bite, as I've long had this same question. So the short answer is, it looks up the hash in the hidden services directory (iirc it's a distributed hash tab

I'll bite, as I've long had this same question. So the short answer is, it looks up the hash in the hidden services directory (iirc it's a distributed hash table of sorts): https://tor.stackexchange.com/questions/711/onion-domains-dns-lookup https://tor.stackexchange.com/questions/711/onion-domains-dn... But what the heck is the hidden service directory? This explains it better than I can at the moment: https://2019.www.torproject.org/docs/onion-services https://2019.www.torproject.org/docs/onion-services As I understand it, Bob's tor software sets up entry points on the tor network, which don't know where Bob is, but know how to get to a circuit which can get to Bob, like regular Tor. Bob signs those entry points and publishes to the DHT. Alice's client asks the DHT for the entry points to the .onion hash. The entry points can then route Alice's traffic to Bob. I hope someone can further unpack this :)