With our current tools it’s relatively easy to examine the performance of a single page, or the performance of a journey a visitor takes through a series of pages but when I examine a client’s site for the first time I often want to get a broad view of performance across the whole site.
There are a few tools that can crawl a site and produce performance reports, SiteSpeed.io from Peter Hedenskog and NCC Group’s (was Site Confidence) Performance Analyser are two I use regularly.
Sometimes I want more than these tools offer - I might want to test from the USA or Japan, or want some measurements they don’t provide - that’s when I use my own instance of the HTTP Archive.