Products / Probe network
Where the checks come from
Every scan runs on our probe, a small program on AWS Lambda that makes the request and reports exactly what came back. It runs in the regions below. The Down Checker and the Response Time Checker can ask every region at once, so a site that fails in one part of the world shows up as down there and up elsewhere.
Loading the probe network…
How to read it
The default region answers every scan. The others are asked only when you tick "From every region", and each answers once: one more request, not three, so the speed numbers from other regions are single samples beside the main median.
IPv6: a region with an IPv6 route also checks a site over IPv6 when the site publishes an IPv6 address, and shows both side by side. Post-quantum TLS: a probe on Node 24 can offer the hybrid key exchange X25519MLKEM768, which the SSL Checker uses to tell you whether your server accepts it.
Our probes identify themselves with the User-Agent BCDRPulseHeaders; see the bot page to allow or block them.