What happens during a check
The page requests /health.txt seven times with caching disabled. The browser measures each completed round trip. Northstar reports the median, approximate jitter and the slowest observed sample.
What never happens
There are no third-party scripts, analytics pixels, advertising calls, accounts or telemetry uploads. Results remain in JavaScript memory for the life of the page and are discarded when it closes.
It confirms that DNS, a secure browser connection and this origin worked from this browser at that moment. It does not certify unrelated destinations or every network path.
Why results can change
Access networks, DNS caches, radio conditions, congestion and route selection all vary. A single measurement is a snapshot. Repeat checks and compare from the same access network before drawing conclusions.
Data returned by the origin
The health object contains only the text ok. Standard web-server access logs may contain ordinary request metadata needed for operations; the page itself adds no identifier.