Azure latency test

Is this an Azure ping?

Every Azure region answers 401 on its live-diagnostics host — a control-plane host in two of them — and that 401, timed, is the closest a browser can get to an Azure ping. ICMP is not available to a web page at all. The status code does not matter to a stopwatch: the round trip is what is being measured.

How Azure is probed

{region}.livediagnostics.monitor.azure.com answers 401 from inside the region — every resolved IP was checked against that region's own Service Tags prefix. No CORS headers, so it is timed blind.

The first request of a sweep is discarded — it pays for DNS, TCP and TLS — so every sample after it is essentially one round trip, and the reported figure is the fastest of them.

Every Azure region

Prefix counts come from Azure’s own published feed. Each region links to its distance, its physical floor and the endpoint used to time it.

Measure it yourself

Open the instrument, select Azure, choose regions and run a sweep. Nothing is pre-selected and nothing runs until you press the button.