ERR_CONNECTION_TIMED_OUT on Chrome
Why it happens on Chrome
Chrome's prediction service and a full socket pool can hold a dead connection open, so the timeout repeats in Chrome while the site loads elsewhere.
The fix on Chrome
Test the URL in an incognito window with extensions disabled. If it loads, an extension or a stale socket pool is the cause — flush it at chrome://net-internals/#sockets.
Is ERR_CONNECTION_TIMED_OUT happening on your domain?
An uptime probe from outside your network tells you whether the server is unreachable for everyone or only from where you are sitting — which is the first fork in every timeout diagnosis.
Free, no signup. Runs from outside your network, which is the only way to tell a server fault from a local one.
If that didn't fix it
Chrome has its own failure mode, but ERR_CONNECTION_TIMED_OUT has a wider set of causes that apply everywhere. The most common one overall is: the origin server is down or the web server process has stopped.
All causes and fixes for ERR_CONNECTION_TIMED_OUT