isitdown

Ask your assistant "is X down?" and it runs a live HTTP check from Singapore and Boston. That way a site blocking one region isn't reported as an outage. It can also list which of 634 popular sites are down right now, show a site's uptime history and recent incidents, and report when a site's TLS certificate expires. No API key and no sign-up. It's the same free public API that downforjustmeoreveryone.com runs on.