Chapter 6
Having Fun: Lets Analyze the Critical Rendering Path Together
Section 9
Time Phases - Detailed Explanation
We have seen that all network requests are considered resources. As they are retrieved over the network, resources have distinct lifecycles expressed in terms of resource timing. By default, Chrome breaks down the life of a request into different parts as follows: Queueing and Stalled which basically show the time a request needs to wait before being acted on by the browser. DNS Lookup, Initial Connection, and SSL, which show the time spent in these respective parts of the request lifecycle. Request Sent is the amount of time the browser takes to send the request to the server. Waiting (TTFB) is the amount of time the browser has to wait before beginning to receive data from the server. Content Download is the amount of time it takes to receive the entire resource from the server.