Beyond Core Web Vitals: A Report from performance.now() 2024

For the third time, I attended Europe’s most prestigious conference on "web speed".

The conference was held for the fifth time in Amsterdam, within the extraordinary setting of the former church, Zuiderkerk. It’s a place where the very atmosphere seems to ignite the neurons in your brain.

The organisers handled everything with absolute aplomb. The schedule flowed seamlessly, with the programme having just the right amount of drive.

Some talks were so packed with insights that I watched with bated breath. Attempting live reporting for my colleagues at PageSpeed.ONE, I found it quite the challenge to keep up at times.

What did the fifth year offer us?#

Thanks to diligent note-taking, I have compiled a list of what I consider the best talks.

Tammy Everts - The Web Performance Landscape in 2024#

There might be no better format to kick off a web speed conference than this. Tammy summarises the current state of web speed and offers intriguing insights and global statistics. She also introduced a topic that resonated throughout the conference. Everyone perceives speed differently. Younger generations are increasingly impatient, accustomed as they are to fast internet.

Harry Roberts - Site-Speed That Sticks#

Anyone who has seen Harry present knows it's a guarantee of quality. This time, Harry chose a different format than what we’ve seen, for example, at our Webexpo.

The talk drew from his consultancy experience. He often battles with clients whose websites begin to slow down again after six months. Harry is therefore developing a framework aimed at establishing a proper web performance culture. In my view, it was quite inspiring.

Paul Calvano - Performance Mistakes#

With new features and APIs in browsers, tuning speed is becoming increasingly straightforward. Yet, despite these advances, developers often incorrectly implement new features, leading to performance losses.

Paul, using data mined from the HTTP Archive, presented 17 common mistakes. He found, for instance, that 50% of websites prefetch third-party domains without using the crossorigin attribute.

Human patience is now a significant topic. Our expectations are set by what we consider standard. Once exposed to a new standard for some time, we quickly adapt and are reluctant to revert. Thus, tuning speed becomes somewhat of an endless race.

Jack Franklin - DevTools Deep Dive#

The Performance panel in Chrome DevTools is an invaluable tool for diagnosing and optimising website performance. This talk delves deeply into its features and introduces novelties that will delight all developers.

The new sidebar Insights, for instance, aids in tuning the LCP metric. Consultants will also appreciate the "annotations" that can be added to graphs.

Erwin Hofman, Karlijn Löwik - INP Case Studies#

The year 2024 was a milestone for the Interaction to Next Paint (INP) metric. In March, it was officially included in Core Web Vitals.

The proportion of websites with this metric in the green zone increased by 10% over the year. The talk showcased a wealth of practical statistical information.

Perhaps the most interesting finding for me was that HotJar is one of the slowest third parties and that 50% of INP occurs after 10 seconds spent on a site.

Annie Sullivan - Aiming for the Stars#

Just as Tammy expertly opened the conference, Annie closed it in grand style.

Annie Sullivan is a force that has been driving the web platform forward for 20 years, so I was eagerly anticipating her talk. She reminded us that tuning speed is an iterative process that must focus on real users and conversions.

Google already suspects that good Core Web Vitals limits and the 75th percentile are just a decent start and reminded us that users will continue to become more demanding. She shared the tool perfetto, which Google uses when the performance timeline doesn’t reveal enough information.

You can now watch all the talks on YouTube.

If you're interested in the 2022 report, read Zuzana Šumlanská's notes.

Tags:Web Performance