Nexus Market “Checking your browser” — what the L7 challenge is, why it exists, what to do
The most-asked operational question fielded by the newsroom: what is the “Checking your browser” page that appears between Tor Browser and the Nexus login screen? Editorial answer in full.
The page is the platform's layer-7 anti-DDoS challenge. It runs in front of the Backup A and Backup B mirrors during elevated traffic windows; the headline mirror serves it intermittently. The challenge holds your request for a small window (typically 5–10 seconds), evaluates browser-side characteristics that are cheap for a real browser and expensive for an attack tool, then either passes you through or asks you to retry on a fresh circuit.
The page is not a phishing screen. The standard fingerprint footer is present below the challenge text; if the signature on that 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 from the Tor Browser menu and retry. If three retries fail in succession, switch to the headline mirror.
Verified working Nexus Market mirrors
Three v3 onion addresses currently serving the production market, signed under PGP fingerprint 0x7F2A0A9D. Use the Copy buttons.