.onion version 3 addresses are 56 characters. As far as I understand they're based on a public key so you'd have to brute force creating key pairs until you end

.onion version 3 addresses are 56 characters. As far as I understand they're based on a public key so you'd have to brute force creating key pairs until you end up with a fitting address. Duckduckgo for example is duckduckgogg42xjoc72x3sjasowoarfbgcmvfimaftt6twagswzczad.onion