Web performance is crucial for providing users with a smooth browsing experience. One important metric that impacts performance is Largest Contentful Paint (LCP), which measures when the primary content loads. In a recent webinar, experts from Google and NitroPack conducted an in-depth exploration of LCP to help site owners optimise it.
A Comprehensive Overview of Largest Contentful Paint L.C.P
The webinar began with Barry Pollard, Developer Advocate at Google, explaining what exactly Largest Contentful Paint measures—the load time of the largest content element on a page. As Pollard explained, this could be text blocks, images, videos and more.
Pollard noted that Largest Contentful Paint is one of Google’s Core Web Vitals metrics that aims to quantify user experience. According to Google, a “good” LCP is under 2.5 seconds while over 4 seconds is considered “poor”. He explained that Largest Contentful Paint was launched in 2020 as part of providing site owners with actionable, user-centric data.
Pollard also clarified that LCP can differ across devices and browsers. This underscores the importance of using real user data from the field versus simulated tests.
Latest Updates to the Largest Contentful Paint Metric
Adam Silverstein, Developer Advocate at Google, outlined notable updates to how LCP is calculated in recent WordPress releases:
- Videos now use first-frame load time instead of just poster image load
- Animated GIFs use first-frame load time instead of waiting for complete load
- Low-quality placeholder images are excluded from measurement
- Browsers try to predict and prioritise loading potential LCP elements
While these changes likely improve accuracy, Silverstein did not explicitly state they make Largest Contentful Paint easier to pass.
Why LCP is Challenging to Optimise
Ivailo Hristov, CTO of NitroPack, explained that many factors outside a developer’s control can impact Largest Contentful Paint scores. These include:
- Network quality and user location
- Device performance
- Redirects from external sites
- Third-party scripts
Hristov emphasised that understanding real user experience is essential to improving LCP, as simulation tools alone are insufficient.
Strategies Suggested for Improving Largest Contentful Paint
The experts suggested four optimisation strategies:
- Reduce Time to First Byte: Leverage caching, a CDN, and limit redirects to improve baseline.
- Eliminate Resource Load Delay: Preload key images, fonts, and videos. Don’t lazy-load LCP images.
- Reduce Resource Load Time: Compress images, optimise fonts, and use browser caching.
- Eliminate Render Delay: Defer non-critical JavaScript, create critical CSS, and remove unused code.
They referenced example sites when discussing these techniques. However, the transcript does not show they demonstrated live implementations and quantified specific LCP reductions.
Key Takeaways from LCP Webinar
The webinar provided insights into strategies for optimising Largest Contentful Paint based on real-world user experiences. As the experts emphasised, with user expectations higher than ever, ensuring main content loads quickly is essential.
While Largest Contentful Paint can be challenging to improve due to external factors, the optimisation techniques covered may help boost scores. By leveraging field data and making incremental improvements, developers can strive to create fast, frustration-free user experiences.
