Error messages

ERR_CONNECTION_TIMED_OUT in Chrome on Mac

Chromium describes this error as: “A connection attempt timed out.” Chrome found the address, but the server did not answer in time.

Applies to: Google Chrome and other Chromium browsers on all current macOS versions.Checked: 29 October 2026

Symptoms

A firewall that drops the connection. A company, school or hotel network can drop traffic to some sites or ports.
A broken IPv6 path. The site has an IPv6 address, but IPv6 does not work on your network.
A VPN or proxy. Traffic goes through a VPN or proxy that cannot reach the server.
A Wi-Fi login page. Some public networks hold traffic until you sign in.
The server is down. If every network fails, the server does not answer.

Open the same address on another device on the same network. If it fails there too, the problem is the network or the server.
Test the port from Terminal, with a 5-second timeout.
```
nc -vz -G 5 example.com 443
```

Try IPv4 only, then IPv6 only.

curl -4 -I https://example.com
curl -6 -I https://example.com

If you are on public Wi-Fi, sign in to the network. See Wi-Fi login page does not appear on a Mac.
If only IPv6 fails, read IPv6 problems on a Mac.
If a VPN, proxy or security app is on, turn it off for a short test. Turn it on again after the test.
If a company network blocks the site, ask the administrator.

Kilobat's connection doctor tests the site layer by layer: network, proxy, DNS, rules, IPv4, IPv6, TLS and the server. It names the layer that failed.
```
kilobat why https://example.com
```
These Kilobat checks are free. AI agents run them through MCP with diagnose_connection and diagnose_network. See Find why one site or API won't connect.

Is a timeout different from a refused connection?

Yes. A refused connection gets an answer at once. A timeout gets no answer, which often means that something drops the traffic.

Sources checked on 29 October 2026. Man pages are the ones installed with macOS; open one with man <name> in Terminal.