Check a site from outside your network: whether it responds, with what status, through which redirects - and a timing waterfall showing exactly where the milliseconds go.
This check runs from AlertKick's infrastructure, not your machine - so it answers the question your own browser can't. If the check succeeds while your browser fails, the problem is on your side: local DNS cache, VPN, office firewall, or ISP. If both fail, the site is genuinely unreachable from the outside, whatever its own dashboard says from inside the network.
Each phase points at a different suspect. DNS slow: your resolver records or their DNS provider. TCP connect slow: network distance or a struggling host. TLS handshake slow or failing: certificate or proxy trouble - run the SSL checker next. Time to first byte slow: the application itself - the server got the request and took that long to think; databases and cold caches live here. A healthy small site lands under ~500ms total from a nearby region.
Note that a 200 OK proves the server answered - not that the page works. Apps serve styled error pages with 200 codes all the time, which is why real monitoring pairs the status check with a keyword check. The website monitoring setup guide covers the full checklist.
A one-off check tells you about now. An AlertKick uptime monitor runs it continuously from multiple locations, requires two to agree before alerting, watches response-time trends and your SSL expiry, and pages you through escalations when it matters. Free.
Monitor this site - free