An updated overview of image loading optimization methods to improve LCP.

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In short, we wanted our list of top web performance recommendations to focus on:

• Recommendations we believe will have the largest real-world impact
• Recommendations that are relevant and applicable to most sites
• Recommendations that are realistic for most developers to implement

Priority Hints are used to indicate to the browser the relative priority of a resource. I take a deep dive into how you can improve your Largest Contentful Paint by using fetchpriority.

Designing, developing or leading a web project (or an app) have inherent constraints, and adding to them might take time and resources you do not have. On the other hand, avoiding non-quality can bring you much in lost revenue through better position on search engines, better compatibility, speed and accessibility leading to a lesser quit rate, or better word-of-mouth following great after-sale service.

A tree view (collapsible list) can be created using only html and css, without the need for JavaScript. Accessibility software will see the tree view as lists nested inside disclosure widgets, and the standard keyboard interaction is supported automatically.

For technical teams I advise to additionally track LCP(FE), or the Front End Component of LCP.

If nothing else, my hope is that this post helped shed some light on the fact that LCP is, by its very nature, a dynamic metric that is heavily dependent on user behavior. You can’t always know ahead of time what the LCP element is going to be for a given page, so it’s important that your optimization techniques can handle a range of possible outcomes, and adapt accordingly.

When measuring web performance, we often try to get a single number that we can trend over time. This may be the median page load time, hero image time, page speed score, or core web vitals score. But is it really that simple?

– Collect user errors
– Normalize & De-duplicate
– Cluster similar errors
– Measure User Impact
– Handle Script Error

When it comes to error handling, it truly is a team sport

Creating a performance story can only start with the data. Having a better understanding of your app’s state and continuously measuring and monitoring it is key to making sure you can ship the most impactful results to your users.

via Perf NL (https://calibreapp.com/newsletter)

Accessibility is a holistic practice that touches every aspect of creating a digital experience. This means it is also a backend web development consideration

via Perf NL (https://calibreapp.com/newsletter)

Finding out how browser and proxy caches behave (and misbehave)

You probably heard about the stories of Walmart that increased their conversion rate by 2% for every less second their page would take to load. While we found a clear correlation between page…

Progressive enhancement. Because sometimes your JavaScript just won’t work.

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:

🧞 Phenomenal Cosmic Powers, Itty Bitty Living Space

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.