Every marketplace address ends in .onion and looks like a random string of letters and numbers. For v3 addresses, that string is exactly 56 characters long. Unlike traditional domains that map to an IP address via DNS records, an onion address is derived from cryptographic material. Specifically, it acts as a truncated hash of the hidden service public key. The length matters because it must balance collision resistance with usability. Shorter strings risk collisions where two services share an address. Longer ones become harder to type manually or remember if you cannot copy-paste. Fifty-six is the current standard defined by the Tor project for version three circuits.
Why normal browsers fail
If you paste an .onion URL into Chrome or Firefox without the Tor extension, you get an error. Usually it says the server name could not be resolved. Technically, your DNS query returns NXDOMAIN. There is no A record or CNAME entry for that name anywhere in the global Domain Name System hierarchy. Standard DNS resolvers look for the address in their central database, find nothing, and report failure. They do not know about Onion Routers. They do not speak the protocol needed to establish a circuit through anonymous relays. Without the specific client software that speaks this protocol, the text is just a string. It has no routing instructions attached to it for ordinary TCP/IP traffic.
Finding the service through consensus
Tor handles resolution differently. Instead of asking a central authority, your Tor client asks for the current consensus file. This is a list signed by authorities detailing which nodes are available and their capabilities. Hidden services publish their public keys to these authorities. Your client searches the consensus data to find which node holds the introduction point associated with the private half of the key pair. It then builds a path of seven hops. Three guards, middle relays, and finally an exit node that connects to the hidden service's introduction point. The final hop talks directly to the target, but neither end knows the full path of the other. To see valid links formatted correctly, check the list of current onion links. Understanding this structure helps when troubleshooting, as described in the access guide.