EXPLAINER Nexus Market “Checking your browser” — explainer thread
The “Checking your browser” page sits in front of backup A and backup B mirrors during elevated traffic. It is a layer-7 challenge that verifies you are a real browser before passing through to the login page. It is not a phishing screen. Wait the 5–10 second window, the page reloads itself, you go through. The standard signed timestamp footer is present below the challenge text on the real challenge; if your block verifies cleanly, you are on a real Nexus mirror.
If the page hangs more than 30 seconds, refresh once. Still hanging? Open New Tor Circuit for this Site and retry. If three retries fail, switch to the headline mirror (the L7 challenge runs less aggressively there). The full discussion thread on this is the explainer pinned in mid-cycle whenever a fresh wave of newcomers misreads the challenge as phishing.