onejob.fyi / Cloudflare error explainer
Cloudflare: Partial System Outage · live

Error 521: the website’s server refused the connection.

or paste the whole error page
Where it broke: at the website
You your browser ✓ Cloudflare the edge in between ✓ The website the site’s own server ✕

The website’s server refused the connection. Not you.

Cloudflare tried to reach the website’s server and the server actively said no — it is off, or it blocks Cloudflare. If the server is restarting, minutes. If it is switched off or blocking Cloudflare, it stays down until the owner acts.

What to do about a 521

  1. Wait a few minutes and reload once.
  2. Tell the site owner.Copy the report below; the Ray ID tells them exactly which request failed.

Nothing on your side causes this. VPN, cookies and browser do not matter here.

521 — if you run this site

  1. The web server process is not running
  2. The origin firewall blocks Cloudflare’s IP ranges
  3. The server listens on a different port than Cloudflare expects

Allow Cloudflare’s IP ranges through the origin firewall and make sure the origin accepts connections on ports 80/443 from them; verify the DNS record points at the right server.

Cloudflare’s documentation