Why not "down for everyone"? Real multi-location checkers (like the well-known "down for everyone or just me" sites) run checks from many servers around the world. A page running in your browser can only ever check from your own connection — if a site is blocked in your country/network but fine elsewhere, this will report it as "down" even though it's actually just you. Treat a "down" result here as "unreachable from here," not a global outage confirmation.
Sends 3 real requests and reports up if any get a response. Browser CORS rules mean the response content can't be read, only whether it arrived — enough to tell reachable from unreachable.
