Measure DNS lookup, TCP connection, TLS handshake, and server response time for any URL.
Time to First Byte is how long the browser waits before the server's first response byte arrives. It covers DNS resolution, the TCP connection, the TLS handshake and the server's own processing time — everything that happens before rendering can even start. The measurement runs from a Cloudflare edge location, so it reflects a well-connected visitor rather than one particular network.