Latency
The tool sends sequential requests to one tiny same-origin endpoint and reports the median successful browser HTTP round-trip time. This includes network, CDN, HTTP and browser overhead, so it is an approximation rather than ICMP ping.
Jitter
Jitter is the mean variation between consecutive successful timings from that same probe sequence. It is an application-layer approximation, not UDP or RTP jitter.
Request loss
The loss percentage is the share of measured latency probes that fail. It is application-layer request loss and must not be interpreted as raw packet loss.
Service checks
Configured services are checked once each for browser reachability. Their response times are shown separately and never enter the latency, jitter or request-loss calculations.
Download and upload
Quick checks use small transfers. Full diagnostics use larger adaptive transfers so faster links have more time to reach representative throughput.
Security signals
The browser can confirm signals such as HTTPS transport, secure-context status and mixed-content exposure. It cannot audit your router, wireless encryption, DNS path or local network.