ERR_CONNECTION_REFUSED

Plain-English meaning

Browser could not open a TCP connection to host/port.

Why it happens

Target is not listening or firewall actively rejects the connection.

Common causes

  • Service crashed or failed to start
  • Service bound only to localhost
  • Container port not published
  • Security group/firewall denies inbound port

What to check first

Use curl/nc from same network path, verify listening sockets, and check container/LB port mappings.

How to fix it

Start service, bind to correct interface, expose required ports, and align DNS/LB targets with active listeners.

Example signal

net::ERR_CONNECTION_REFUSED
GET https://api.example.com/health

Related links

404 · 429 · 500 · 502 · 503 · 504 · Cloudflare 522 · Nginx 499 · ERR_CONNECTION_REFUSED

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