DNS Lookup Time

DNS lookup time is how long it takes to translate the site's domain name into the server's IP address, before any connection is even made.

This is the first link of the loading chain, and its key point is that it is largely out of your hands: the speed of the DNS server's answer and the user's operator network decide it, not your code. The big trap in reading it is a hidden denominator: on a reused connection, or when the result sits in the browser or OS cache, this stage returns zero, so pooling all visits into an average pulls the number falsely low. This is why you count only visits with a fresh lookup and declare that population. A high DNS time usually traces to the operator's DNS quality or the absence of a nearby CDN, and because it varies so much between operators, a per-operator split says more than one overall number.