In this post, I want to look at ways to help mitigate and work around [the fact that site-speed is nondeterministic & most metrics are not atomic]. We’ll be looking mostly at the latter scenario, but the same principles will help us with the former. However, in a sentence:
With both solutions measuring user experience metrics, it is natural to assume that they should be equivalent. It can be confusing when we see differences. This guide will explain why that can happen, and offers suggestions for what to do when the numbers do not align.
Priority Hints are a newly released browser feature, currently available in Chrome and Edge, that give web developers the option of signaling relative load-time priorities of significant page resources. These hints are declared by way of a new "fetchpriority" attribute in the page's HTML markup and are relatively easy to apply.
Early Hints is a recent addition to the HTTP Informational response (1xx) status codes. Information response codes are temporary status codes used to inform the client about the status of the request, while the server is processing the request to send the final response code (2xx-5xx).
Early Hints is specifically used to pass information on the resources that may be preloaded by the client. The client will eventually need these resources when it renders the final response from the server.
CORS (Cross Origin Resource Sharing) enables web apps to securely access communicate across origins. But it comes with a performance penalty. In this tip, we'll discuss techniques for minimizing this penalty!
We are happy to announce that we are open sourcing our first performance quality model that is trained on millions of RUM data samples from around the world free to use for your own website performance optimizations!
By using techniques that assess the performance impact of a build in relation to the performance characteristics (magnitude, variance, trend) of adjacent builds, we can more confidently distinguish genuine regressions from metrics that are elevated for other reasons (e.g. inherited code, regressions in previous builds or one-off data spikes due to test irregularities). We also spend less time chasing false negatives and no longer need to manually assign a threshold to each result — the data itself now sets the thresholds dynamically.
We see in the data that the presence of certain errors lead to actions of user frustration that have bottom line implications for the business serving the site. The two most prominent cases of this are reloads and abandonwments (page exits).”
Why? Because this is pretty hard to “understand” that the page exit or the reload in the SR.
Indeed, we just see the error at the very last second and boom, finish (or next replay start in case of reload)
Today in Lyon, France, was the We Love Speed conference. Its focus is on everything related to web performance. Even if the conference talks were only in French, I'll do this recap in English, to let more people learn from it.
In the new responsiveness metrics, we measure the latency of user interactions, how your customers navigate and act on your website, rather than individual events. A user interaction, such as tap (click), drag, and keyboard interaction, usually triggers multiple events.