Recognising a real Nexus address

Three quick checks to eyeball whether an address is likely a real Nexus mirror before doing full verification:

Prefix. All current Nexus onion addresses start with nexus. This is by operator choice, not by cryptographic requirement, but it is a consistent signal. An address that does not start with those five characters is not a real Nexus mirror.

Length. Exactly 56 characters before the .onion suffix. Not 55, not 57. If your paste ended up with something shorter or longer, you copied wrong or the address is malformed.

Character set. Lowercase letters a to z and digits 2 to 7. No uppercase. No 0, 1, 8, 9. No punctuation. If your address has anything outside this set, it is not a valid v3 onion.

These are eyeball checks, not verification. Any address that passes all three still needs to be checked against the current signed rotation before you type a password on it. But an address that fails any of them is guaranteed wrong.