Run this from the device & network where you experience lag. Nothing is stored.
Sign outMeasuring your connection to our servers.
DNS / TCP / TLS read 0 ms when the browser reuses an existing connection — that's normal. A large TLS or DNS figure points to a slow handshake or resolver. Edge-measured TCP RTT is the round-trip our edge itself measured to you (independent of the browser).
Enter the site you use and we’ll measure how fast it loads from your connection. “Unreachable” means your network couldn’t connect — the site is down, the address is wrong/mistyped, or it’s blocked by your ISP/VPN. Test as many sites as you like.
Resolves the domain from your region and from clean reference networks (US / EU) using each network’s own DNS. If your region returns no answer or a different IP than the rest of the world, your ISP is likely doing DNS-level blocking — switching to a public DNS resolver (DoH) usually fixes that.
Traces the network path from your region toward the site and shows the round-trip time at each hop. The hop with the biggest jump is where most of the delay is added — usually your last mile (ISP / Wi-Fi) or the international gateway out of your region.
Downloads then uploads a few MB of random data to your nearest Cloudflare edge to estimate your line capacity. Uses ~20 MB total — avoid on metered mobile data. This measures your link to us, not to any specific website.
Pings our edge continuously and charts the round-trip. Watch for spikes (Wi-Fi interference) or gaps (dropped packets). Let it run ~20–30s, ideally while you reproduce the lag.