Network Connectivity Test

What is a network connectivity test?

A network connectivity test sends HTTPS requests from your browser to a representative set of websites and measures whether they respond and how long it takes. Domestic sites such as Baidu and Taobao may use different routes from international sites such as Google and YouTube. Proxy clients also route domains according to rules, so one site's result cannot describe the whole connection.

Comparing domestic, international, AI, social, and developer-service groups can reveal route patterns. Domestic sites working while many international sites fail may point to proxy or cross-border routing issues. If international sites work but AI services do not, review the proxy rules for those domains. Domestic sites slower than international ones may indicate that domestic traffic is also passing through an overseas proxy. These are network signals, not definitive diagnoses from a single browser test.

What does this test do?

Each site receives one warm-up request that is excluded from the statistics, followed by up to six HEAD requests. Each request waits up to four seconds, with a short pause between rounds. Up to four sites are tested concurrently to reduce interference from sending many requests at once. The median of successful samples is used as the site's latency. If the warm-up and first two rounds get no response, remaining rounds are skipped. Requests use no-cors mode and omit cookies and the Referer header; the browser can measure completion without reading cross-origin response contents.

How should results be read?

Dots represent individual samples: green is fast, amber is slower, red means that round failed, and an outlined dot means later rounds were skipped after the site was judged unreachable. Latency is the median of successful samples: good is under 100 ms, okay is up to 250 ms, and slow is above 250 ms. A mix of successes and failures indicates an unstable connection. A timeout only means that this browser request did not complete; it does not prove that a site is blocked. Browser extensions, firewalls, target outages, and network changes can also cause failures.