What is DNS lookup time in a web request?

DNS lookup time refers specifically to the duration it takes to resolve a domain name into an IP address during a web request. When a user enters a website address, the DNS (Domain Name System) translates that human-readable URL into a machine-readable IP address, enabling the browser to locate and communicate with the server hosting the requested content.

The choice identifying the time spent on the domain name for the current document accurately captures this process. It focuses on the critical function of DNS in facilitating the connection between a user’s device and the server that hosts the desired website.

The other choices describe different processes involved in the overall experience of accessing a webpage but do not pertain specifically to DNS lookup time. For instance, processing JavaScript is important for webpage functionality but happens after the DNS resolution. Similarly, rendering the webpage and server response times relate to the loading and display phases of web content but are not concerned with the DNS resolution phase itself.