Performance analysis (also known as performance profiling) is the observation and study of resource usage by an application. We will perform profiling in order to identify performance issues in our applications. A different performance profiling process will be carried out for each type of resource using specific tools. We will now take a look at how we can use Google Chrome's developer tools to perform network profiling.
We are going to start by analyzing network performance. Not so long ago, in order to be able to analyze the network performance of an application, we would have had to write a small network logging application ourselves. Today, things are much easier thanks to the arrival of the performance timing API (http://www.w3.org/TR/resource-timing/). The performance timing API allows us to access detailed network timing data for each loaded resource.
The following diagram illustrates the network timing data points that the API provides...