TL;DR: The 2024 predictions for Web Performance Optimization highlight the growing significance of Core Web Vitals, with a spotlight on new metrics like Interaction to Next Paint (INP), tools like the Long Animation Frames API, and AI enhancements for instant loading.
In a day, we flip through ~130 web pages, waiting around 6 seconds for each to load.
This means you spend a staggering 13 minutes hovering over a screen idly every day – and over 17 minutes if you’re on your phone.
It’s no surprise that web performance optimization (WPO) continues to push the envelope in search of better ways to win back some of the lost time. Or at least make sure we wait as little as possible.
Let’s flip through the most notable achievements from the past 12 months and prepare to leverage the subtle trends we see coming in 2024!
The Faster Web: Where Are We Now?
In 2023 alone, the web's performance has undergone a substantial evolution, notably evidenced by the impressive advancements in Core Web Vitals (CWV).
The metrics representing loading speed, interaction responsiveness, and layout stability have set new benchmarks for website performance.
A true testament to this progress is the staggering 10,000 years of waiting time saved – a monumental achievement stemming from the enhancements made to Core Web Vitals.
This massive reduction in waiting time spans across desktop and mobile platforms highlighting the substantial impact these improvements have had on user experience across the entire web.
Moreover, the data from HTTP Archive speaks volumes about the increasing adoption and implementation of Core Web Vitals.
Websites passing the Core Web Vitals assessment have seen a significant upsurge, reflecting a 6% increase in 2023 alone. This leap signals a collective effort from web developers, site owners, and products worldwide to prioritize and optimize their sites for a smoother, faster, and more user-friendly browsing experience for all.
Currently, there are over 6,5 million eligible origins in the Chrome User Experience Report (CrUX).
The State of Core Web Vitals: Retrospective and Achievements
At the start of 2023, 41.8% of websites passed Core Web Vitals. Since then, we have seen steady growth, where desktop pass rates have gone up to 47.4%.
How were these spectacular results achieved? Let’s see what developments Chrome and the wider ecosystem introduced.
Google Chrome Developments
Major advancements came straight from the Google Chrome development team:
- Arguably, the biggest news in Core Web Vitals for 2023 is the official rollout of the new responsiveness metric – Interaction to Next Paint (INP). INP is set to replace FID in March 2024 as a more comprehensive way of measuring all interactions during a session instead of just the first one like its predecessor.
- The introduction of Back/forward cache (bfcache) to the Chrome browser: designed to help you quickly go back or forward in your browsing history without waiting for the page to reload.
Results: BFCache’s hit rate has improved month-over-month on both Android (3.6%) and Desktop (1.8%)
- New PreconnectOnAnchorInteraction feature that connects to origins on pointer-down rather than pointer-up.
Results: Led to a 6/10ms (0.4/1%) median LCP improvement on Android/Desktop and an improvement in cross-origin LCP by ~60ms on both Android and Desktop. The launch also resulted in a 0.08% Content Ad revenue increase.
- Prerendering pages so they load instantly before the user actually visits.
Results: Page loads via typing URLs directly in the omnibox got a 500-700ms (14-25%) median LCP improvement with prerender, moving global median LCP across all navigations by 6.4ms.
Results: Led to improvements in Largest Contentful Paint (LCP) and Interaction to Next Paint (INP)
- Continuous optimizations for Chrome under multiple active tabs
Results: Seen improvements to scheduling and contention, which improved INP by 5% and LCP by 2% in the last 6 months.
- Improvements to the Chrome renderer that alter the priority of task queues for optimal CWV, like high-priority image loading, prioritized compositing after delay, and SVG raster optimizations. All improvements resulted in LCP, CLS, and INP pass rate increases.
WordPress & Core Web Vitals Achievements
In 2023, under the dedicated efforts of the Core Performance team and contributors, WordPress made substantial leaps in improving Core Web Vitals pass rates.
8.25% for desktop and 8.13% for mobile, to be exact.
One of the main goals in the roadmap for the year was to empower site owners to pass the most challenging CWV metric in WP core – LCP.
Many improvements in the core focus on improving server response time, running more efficient databases, improving JS and CSS delivery, and optimizing images:
- Identifying and addressing the largest server response time bottlenecks in WordPress core
- Enhancing PHP performance of block themes
- Supporting Gutenberg Phase 3 with performance-focused guidance, enhancements, and review
- Autoloading WordPress PHP classes
- Exploring ways to improve performance of translations
- SQLite database integration
- Optimizing the autoloaded options database query in WordPress core
- Exploring ways to further enhance database query performance
- Enhancing the Scripts API with a loading strategy
- Eliminating jQuery usage from the frontend in WordPress default themes
- Adding fetchpriority=”high” to the LCP image in WordPress core
- Avoiding to lazy-load LCP / hero images in WordPress core
- Improving the calculation of image sizes attributes
The results?
WordPress 6.3 loads 27% faster for block themes and 18% faster for classic themes, compared to WordPress 6.2, based on the Largest Contentful Paint (LCP) metric.
Breaking it down even further, we see definitive improvement across all Core Web Vitals metrics on mobile WordPress:
- 43.37% pass LCP
- 78.98% pass CLS
- And 97.42% pass FID
As a solution helping 180K+ WordPress site owners achieve great user experience, we at NitroPack are proud to have contributed to CWV improvement on the platform. Prerendering links via the speculation rules API, we’ve seen an 80% LCP improvement and 55% INP improvement in prerendered pages compared to those without any speculative loading.
JavaScript Community for Better Core Web Vitals
As part of the Chrome Aurora project, where Chrome and open-source web frameworks collaborate, we saw successful partnerships with Next.js, Angular, and Nuxt in releasing performance-focused features like:
In 2022, Next.js reports pass rates increased from 20.4% to 27.3%. Angular pass rates have gone up from 7.6% to 13.2%, and Nuxt pass rates went from 15.8% to 20.2%.
In real life, these new features translated into notable Core Web Vitals improvements for enterprise companies like Land’s End and CareerKarma.
After switching to NgOptimizedImage, Land's End championed a 40% LCP improvement on mobile in Lighthouse lab tests and a 75% improvement in LCP on desktop. CareerKarma's LCP, on the other hand, was reduced by 24% when switching to next/script's web worker mode.
“I hereby proclaim 2024 the year of Web Components! Byte-size, dependency-free, JavaScript-optional, framework-agnostic, server-rendered Web Components."
— Stoyan Stefanov, Creator of perfplanet.com, ex-Yahoo, Published JS Author
SEO/SEA and Core Web Vitals: Touchpoints
Core Web Vitals’ importance in relation to SEO (Search Engine Optimization) has long been discussed.
In the wake of April’s updates to the page experience guidelines, a definitive answer is that Core Web Vitals are not a singular ranking factor but rather part of a system that contributes to page experience evaluations.
“The connection between Core Web Vitals and performance in SEO is still hotly debated, with many people suggesting it’s rarely something that’ll directly affect rankings. But I’m happy to say that I’m seeing more and more organizations prioritizing speed improvements, regardless. A faster site means happier users, reduced friction, better eco credentials, and more revenue.”
— Jono Alderson, World-leading SEO Expert (ex-Head of SEO @Yoast)
It’s important to note that relevance remains the deciding factor when ranking a page, as explained by John Muller (Google Search Advocate):
“If website A is faster than website B, but B is more relevant to the search user’s query, website B would still outrank A.”
In a Twitter thread, he also highlighted that “...Core Web Vitals is more than a random ranking factor, it’s also something that affects your site’s usability after it ranks (when people actually visit).”
During his presentation at the Google I/O Extended event in Sydney in June 2023, Tamas Piros also confirmed the importance of Core Web Vitals, saying “... if your site loads slowly, that is going to have a negative impact on your search page ranking results.”
In terms of SEA (Search Engine Advertising), user experience directly correlates with the quality score of your ads. Real-world examples include:
Business Web Vitals: Web Performance Optimization Impact on Bottom Line
In 2023, businesses continued to adopt Core Web Vitals optimization to elevate their bottom line where a 0.1s improvement in load time means:
- Up to 8.6% more pages viewed in a session
- 5.2% improvement in customer engagement
- 8.4% more conversions
- Increase of 9.2% in average order value (AOV)
The most recent WPO case study shows Carpe’s results after optimizing their website for better user experience – 52% improvement in Largest Contentful Paint and 41% in Cumulative Layout Shift, a 10% increase in traffic, a 5% increase in online store conversion rate, and a 15% increase in revenue.
During a webinar with Google on “Core Web Vitals for Your Business” in September 2023, NitroPack shared learnings from in-house studies linking user experience and speed to specific user behavior patterns:
- Users who experienced a load time of 3 seconds or less visited 60% more pages.
- 50% more visitors drop off when a page loads in 3 seconds in comparison with a 2-second page load time.
- Visitors lose patience and disproportionally start to abandon a web page at 2.75s of the page load
We see more businesses shifting from the idea of speed as the end goal and more toward improving how users interact with their websites. Tackling Core Web Vitals issues goes well beyond backend tinkering. In fact, it has found a well-deserved place among business KPIs as well as in growth reports.
The Faster Web in 2024: Predictions
“On top of continuing the existing trend in improvements for Core Web Vitals, I really think 2024 could be the year of the “instant web” with Chrome’s Speculation Rules API hitting the mainstream and making prerender an easy addition for many sites. This will allow more seamless experiences, especially coupled with the multi-page View Transitions API.”
— Barry Pollard, Developer Relations Engineer @Google Chrome
Let’s see which trends will shape 2024 as not only faster, but near instant.
Passing LCP: Focusing On The Right Optimizations
56.4%
This is how many websites pass LCP on mobile compared to 94.2% for FID and 77.2% for CLS. The challenging nature of the LCP metric stems from the complexity of the time spent in loading the largest contentful element.
In 2022, Philip Walton proposed a new way of breaking down this time:
- The time to start receiving content on the client (TTFB)
- The time to start loading the LCP image (resource load delay)
- The time to finish loading the LCP image (resource load time)
- The time until the LCP element is rendered (element render delay).
This allows for granular measuring and helps site owners identify bottlenecks as well as which optimizations would be most effective to improve the LCP score. In November 2023, Estela Franco shared the results from research in milliseconds.
The problem? Resource load delay.
This means we need to focus on loading the largest contentful resource sooner rather than optimizing for load duration.
✦ We predict...
In 2024, developers and site owners alike will focus on improving the discoverability of the LCP element via resource hints and excluding it from lazy loading altogether.
Preparing for INP: The New Responsiveness Metric
Many have already speculated whether or not the sunset of the FID metric will have a big impact on CWV pass rates.
The answer is yes.
Pass rates will drop once INP kicks in (especially on mobile), and developers will have to roll up their sleeves to make sure their CWV assessments stay green.
INP, however, is a great step forward in understanding how users interact with our websites. Since it measures all interactions during a session, site owners will gain more insight into where most delays are happening.
✦ We predict...
In 2024, developers will increasingly leverage scheduler.yield() and Long Animation Frames APIs to break up and reduce long tasks so the main thread is ready to accommodate an interaction without delays.
Better Understanding of Site Performance
With the sophistication of web performance optimization comes the need for improved understanding of what this actually means to site owners.
In 2023, we saw a rising curiosity in how Core Web Vitals fit in the grander business context as a whole.
CrUX, HTTP Archive, Web Almanac, WPO Stats, in-house and public reports, and business insight tools from independent services and plugins – all dedicated to crunching the numbers and providing transparency to site owners’ efforts toward better user experience.
✦ We predict...
2024 will mark a significant step forward in understanding real user experiences on websites, making Core Web Vitals an essential metric for business owners and ecommerce merchants connecting it directly to their bottom line.
“Looking ahead to 2024, I see a positive shift in how we approach web performance. We're moving away from just looking at lab data and focusing more on the actual user experience. It's an exciting time with lots of new ideas coming up to make websites faster for everyone. At NitroPack, we're really happy to be part of this change, helping to make the web a better place for users.”
— Georgi Petrov, CEO and co-founder @NitroPack
The Role of AI: Next Steps In Web Performance Optimization
The AI boom has impacted the whole world and has many business owners thinking about the opportunities it can unlock.
In fact, in 2023 alone, 35% of companies are already leveraging AI in their businesses, with financial services, healthcare, retail, and manufacturing taking the lead in AI adoption.
In web performance optimization, we’ve already seen the first advancements made with the speculation rules API by Chrome. Whether it’s used to automate tasks, improve workflows, and create new services and products, AI in the WPO industry will empower site owners to meet the rising demand for better user experience and loading speed.
Its application in areas like predictive analytics, pattern recognition, and personalized content delivery has significantly improved user experiences.
✦ We predict...
In 2024, AI will be a promising new chapter in optimization strategies – from predictive analytics and pattern recognition to anticipatory functionalities, the advancements will help us understand user behavior better and answer the user needs faster.
Final Thoughts
As 2024 approaches, the focus remains on sustaining this momentum.
Continued advancements and early adoption of the right web performance optimization techniques will pave the way for an even faster and more efficient web experience.
Here’s to a fast 2023, and let’s all work toward an even faster 2024!
