Measures round-trip connection time from your browser to several global regions, so you can see where your network is fast and where it's slow.
Your browser makes a direct HTTPS connection to a fixed endpoint in each region below and times how long the connection takes to complete. Lower is better - it means fewer, faster network hops between you and that part of the world.
What this doesn't measure: this is connection/TLS handshake time, not a literal ICMP ping, and it doesn't measure download bandwidth or speed - a slow result here means a slower round trip, not necessarily a slow connection overall. Results can also vary between runs depending on network conditions at that moment.
High latency everywhere usually just means a naturally longer physical distance or a congested route - it's a different thing from a site being down or blocked at the DNS level. If a specific site won't load but your latency here looks normal, the DNS Lookup tool's reachability check is a better way to investigate that.
Read more: What's a Good Ping? Understanding Network Latency.