What is measured
Your browser opens a connection to a host that genuinely runs inside each region and times a
series of tiny HTTPS requests — the closest a web page can get to ping, since browsers
cannot send ICMP. The first one is discarded — it pays for DNS, TCP and TLS — so every
sample after it is essentially one round trip. Each dot on a row is one of those samples; the
reported figure is the fastest of them, which is the cleanest read on the true path.
Endpoints were chosen by proving they answer in the region, not at an edge. Anycast front doors
that reply from the nearest city were rejected — including ones that answer for region names that
don't exist.
Physics versus network
The grey part of each bar is unavoidable: great-circle distance to the datacentre divided by the speed
of light in fibre, about 200,000 km/s, there and back. The red part is what routing detours,
queuing and server handling added. A region at ×1.2 of light is beautifully connected to you;
×4 means the packets are taking a scenic route.
Distance needs to know where you are, which comes from the network's view of your address — so behind
a VPN, the floor is measured from where your traffic exits, not where you sit.
Move 1 MB
Modelled, not downloaded — no cloud will let a web page pull a test file from every region at once.
Your link speed is measured for real before your first sweep — never assumed — then the transfer is simulated: handshakes, then TCP slow start
doubling its window every round trip, capped by the bandwidth-delay product. That is why a small
file to a far region is slow on a fast line — the round trip, not your bandwidth, is the limit.
Figures marked est come from that model.
Where the regions come from
Nothing here is a hand-typed list. Region names, codes and IP ranges for AWS, Google Cloud, Azure,
Oracle Cloud, DigitalOcean, Akamai (Linode) and Vultr are pulled from each provider's own published
feed by scripts/refresh_data.py, and re-pulled in your browser where the provider allows it.
Corrections welcome — a wrong datacentre coordinate, a better probe endpoint:
contact@regionlatency.com