Refused in Docker only?

Publish ports (-p) and ensure the service binds to 0.0.0.0 inside the container.

Try [::1] vs 127.0.0.1 and ensure dual-stack listeners.

Works on Wi‑Fi not mobile?

Hairpin NAT or CGNAT can block self-connections to your public IP.

Error fix

Nothing accepted the TCP connection on that host:port—service down, wrong port, or firewall.

Start here first. Step 1 fixes most cases—then work down the list.

Why this works

These steps work because it rules out local security software dropping the connection.

The OS actively refused the connect()—different from timeout (no SYN) or reset mid-flight.

Service not listening
App crashed, wrong bind address (127.0.0.1 vs 0.0.0.0), or wrong port.
Firewall
Security group, ufw, or corporate filter blocks the port.

Reach the listener
1. Verify process is running and listening (ss -lntp / netstat).
2. Open firewall rules for the intended port and interface.
3. Confirm you target the correct hostname (localhost vs LAN IP vs public DNS).

Refused in Docker only?: Publish ports (-p) and ensure the service binds to 0.0.0.0 inside the container.
IPv6 vs IPv4?: Try [::1] vs 127.0.0.1 and ensure dual-stack listeners.
Works on Wi‑Fi not mobile?: Hairpin NAT or CGNAT can block self-connections to your public IP.

Still stuck? Try these related fixes next.

Tweak the message and run again—we'll match an existing fix or generate a new page.

Original error message

ERR_CONNECTION_REFUSED