What a Mars Market onion address is
The string you paste into Tor Browser is not a domain. It is a 56 character name derived from a cryptographic key, and the difference matters the first time a fake one shows up.
A name, not a website
A normal web address is a name that a registry maps to an IP address. An onion address is different: it is the base32 encoding of a 32 byte ed25519 public key, with a version byte and a checksum folded in. That is why a version 3 address always lands on 56 characters before the .onion. There is no registrar to renew it and no whois record to look up.
The practical consequence is that the address does not point at a machine. It points at a routing path. The same market can sit behind three of these names at once, and the storefront, the wallet and the order history behind each of them are the same records, because all three resolve to the same hidden service.
The parts you can actually check
| Prefix | mars. Four characters, produced by generating key pairs until the name started with the word. Every Mars address shares it, which is why it is the first thing a clone copies. |
|---|---|
| Middle | 48 characters of the encoded public key. This is the part that differs from one mirror to the next and the part a copied prefix cannot imitate. |
| Tail | The final characters of that same key. Compare the prefix and the tail against a signed announcement and the middle falls into place or does not. |
| Total | 56 characters before .onion, which marks it as a version 3 hidden service rather than the older 60 character version 2 form. |
Why the market runs more than one
The three addresses on this site are not three copies of the shop. They are three doors into one hidden service, each with its own key pair. The reason to keep several is redundancy against a bad routing path and against an address that has sat in a bookmark for a year and stopped resolving.
When the operator retires one of the doors, the change is announced as a signed post on the Dread forum. This page picks up a new address within an hour of that post. A list from a few months ago will not match the current one, and that is normal.
When the address is right but the page is not
The most common failure is not a wrong address. It is a bad circuit. Tor builds a fresh path on every connection, and a path that routes through a congested or blocked node will hang on the loading spinner while the address in the bar is perfectly correct. Closing the tab and opening a new one forces a new circuit, which clears it more often than a reload does.
The second common failure is the security slider. If the slider is on the highest setting and the page you are trying to reach needs a little JavaScript, the page loads half way and stops. The market is built to run with scripting off, so this is rare, but it is the one setting worth checking before you assume the address is dead.