Karlijn Löwik | RUMvision | The State of Web Performance in 2024

Summary

In this engaging presentation, Carol Leck, CEO of a web performance monitoring company, discusses the state of web performance in 2024. She emphasizes the importance of real user monitoring (RUM) over synthetic data, highlighting the significance of Core Web Vitals for improving user experience and conversions. Leck provides practical tips for enhancing performance, such as prioritizing content for Largest Contentful Paint (LCP), addressing Cumulative Layout Shift (CLS), and optimizing Interaction to Next Paint (INP). She also underscores the impact of third-party scripts and the benefits of using RUM to ensure a website provides the best experience across various devices.

Takeaways

• 🌐 The speaker, Carl, is the CEO of a company that offers real user monitoring to visualize and compare web performance metrics.
• 🎉 Carl starts with a quiz about web performance, highlighting the importance of core vitals over Lighthouse scores in evaluating user experience.
• 📈 Web performance is about perceived performance, focusing on how users experience a site's load time and interactivity.
• 💹 Good web performance can significantly improve conversions, with research showing that faster load times can boost mobile revenue and reduce bounce rates.
• 🔍 Google's core vitals are a set of metrics that measure real user experiences, including Largest Contentful Paint (LCP), First Input Delay (FID), and Cumulative Layout Shift (CLS).
• 🚀 LCP is crucial as it indicates when the main content of a page is visible, and optimizing it can be achieved by prioritizing critical content and avoiding lazy loading.
• 🔄 Cumulative Layout Shift measures unexpected layout changes that can annoy users, and can be mitigated by reserving space for elements that load later.
• 🤖 JavaScript can be a significant bottleneck in web performance, often causing delays in rendering and painting, impacting FID and CLS.
• 🌐 Field data is more representative of real user experiences compared to synthetic data, and should be prioritized for accurate performance measurement.
• 📊 Third-party scripts can have a substantial impact on web performance, and monitoring their effects can help in optimizing the user experience.
• 🏆 Carl's company was featured on Google IO twice, emphasizing the importance of using real user monitoring (RUM) and field data for performance optimization.

Q & A

Who is the speaker in the transcript and what is her role?

The speaker is Carol Leck, the CEO and co-founder of Rion, a company that offers Real User Monitoring to visualize and compare Core Web Vitals and other user experience metrics.

What is the main topic of Carol Leck's presentation?

The main topic of Carol Leck's presentation is the state of web performance in 2024.

What is Carol Leck's mission according to the introduction?

Carol Leck's mission is to make web performance more accessible and to advocate for more women in tech.

What does 'sucks' stand for in the context of the presentation?

'Sucks' stands for Speed User Experience.

Why is good web performance important according to the presentation?

Good web performance is important because it improves conversions, enhances user experience, and impacts SEO rankings.

What are Core Web Vitals and why are they significant?

Core Web Vitals are a set of metrics introduced by Google to measure user experience on the web, including Largest Contentful Paint (LCP), First Input Delay (FID), and Cumulative Layout Shift (CLS). They are significant because they help quantify user experience and are used as ranking factors by Google.

What challenges are associated with relying on Google’s field data for web performance?

The challenges include the data being 28 days behind, inability to differentiate between first-time and returning users, and not being able to zoom in on specific page templates or user experiences.

Why does Carol Leck criticize the reliance on Lighthouse scores for measuring web performance?

Carol Leck criticizes the reliance on Lighthouse scores because they can be easily manipulated and do not represent real user experiences as accurately as field data from Core Web Vitals.

What are some tips provided for improving Largest Contentful Paint (LCP)?

Tips for improving LCP include ensuring the browser finds necessary resources quickly, using priority hints for important elements, avoiding lazy loading for LCP elements, using server-side rendering, and optimizing images and videos.

What is Cumulative Layout Shift (CLS) and why is it important to manage?

Cumulative Layout Shift (CLS) measures unexpected shifts in page layout during loading. Managing CLS is important because these shifts can be annoying and disruptive to users, affecting their overall experience.

How does Interaction to Next Paint (INP) differ from First Input Delay (FID), and why is it important?

Interaction to Next Paint (INP) measures the time it takes for a page to visually respond to user interactions, whereas First Input Delay (FID) measures the time from when a user first interacts with a page to when the browser can begin processing that interaction. INP is important because it provides a more comprehensive view of interactivity by considering the visual response.

What role do third-party scripts play in web performance, according to the presentation?

Third-party scripts can significantly impact web performance by increasing load times and adding complexity to the page, potentially slowing down user interactions and increasing INP.

How can developers address issues with third-party scripts to improve web performance?

Developers can address issues with third-party scripts by monitoring their impact, optimizing their use, and working with third-party providers to reduce their performance footprint. Tools like Real User Monitoring (RUM) can help visualize and measure the impact of these scripts.

What is the significance of Google's I/O event mentioned in the presentation?

The significance of Google's I/O event is that Rion was featured twice for its work in improving web performance, highlighting the importance of using Real User Monitoring (RUM) and field data over synthetic data for performance optimization.