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
The diagnostic first attempts FAST/Netflix Open Connect with adaptive browser progress and stability checks. If the undocumented discovery or target path is unavailable, it automatically uses Cloudflare fallback transfers. Quick FAST runs stop within 12 seconds and Full runs within 30 seconds, while Cloudflare uses fixed 4-second and 8-second windows. The selected provider is shown with the result because different server networks can produce different estimates.
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.