Website Future-Proofing: Optimizing Performance for Core Web Vitals in 2024

Korovkin Vitaliy -

In the ever-evolving landscape of web development, optimizing for Google Core Web Vitals has become extremely important. These metrics, introduced by Google, are crucial for ensuring a superior user experience and improving search rankings. This article explores the latest strategies and techniques to enhance your website's performance, focusing on these essential metrics.

Understanding Google Core Web Vitals

Google Core Web Vitals are a set of specific factors that Google considers essential in a webpage's overall user experience. These vitals are:

  1. Largest Contentful Paint (LCP): Measures loading performance. An ideal LCP should occur within 2.5 seconds of when the page first starts loading.
  2. Interaction To Next Paint (INP): Assesses interactivity. Pages should have an INP of less than 200 milliseconds.
  3. Cumulative Layout Shift (CLS): Evaluates visual stability. Pages should maintain a CLS of less than 0.1.

These metrics collectively ensure that websites are fast, responsive, and visually stable, enhancing user satisfaction and engagement. Let’s learn more about each of them.

Largest Contentful Paint

This Vital measures the time it takes to render the largest image or text block in the visible area of the viewport, starting from the moment the user first navigates to the page. The longer it takes for these large elements to load, the less user-friendly the site is.

Threshold values for Largest Contentful Paint:

  • up to 2.5 seconds — good;
  • between 2.5 seconds and 4.0 seconds — needs improvement;
  • more than 4.0 seconds — poor result, the page needs optimization.

Interaction to Next Paint (INP)

It is measured in milliseconds, representing the time needed for a user to start interacting with the content on the website. The less time it takes for the page to be ready for use, the sooner the user can begin interacting with it and spend less time waiting for the full page load. If a user must wait for the entire site to load before being able to use it, this makes the site inconvenient and negatively affects the user's experience.

Threshold values for Interaction to Next Paint:

  • 200 milliseconds or less indicates excellent page responsiveness;
  • between 200 and 500 milliseconds suggests that the page's responsiveness needs improvement;
  • exceeding 500 milliseconds signifies poor page responsiveness.

What’s the difference between INP and First Input Delay (FID)?

INP (Interaction to Next Paint) is a metric that replaces First Input Delay (FID). While both are responsiveness metrics, FID only measured the input delay during the first interaction on the page. INP improves upon FID by tracking all interactions on the page, from input delay to the time required to start event handlers, and finally until the browser renders the next frame.

These differences mean that INP and FID represent different types of responsiveness metrics. FID was a load responsiveness metric designed to assess the first impression of a page for the user, whereas INP is a more reliable indicator of overall responsiveness, regardless of when interactions occur throughout the page's lifecycle.

Cumulative Layout Shift

CLS measures the largest burst of layout shift scores for every unexpected shift throughout the lifecycle of a page.

A layout shift occurs whenever a visible element changes its position from one rendered frame to the next.

A burst of layout shifts, known as a session window, occurs when one or more individual layout shifts happen in quick succession, with less than 1 second between each shift and a total duration of no more than 5 seconds.

Threshold values for Cumulative Layout Shift:

  • up to 0.1 – good;
  • from 0.1 to 0.25 – should be improved;
  • more than 0.25 – bad result, you need to optimize the page.

The largest burst refers to the session window with the highest cumulative score of all layout shifts within that window.

Tools to measure and improve Core Web Vitals

  • PageSpeed Insights: allows you to measure site loading speed and important SEO metrics, including Core Web Vitals. Provides detailed insights and suggestions to improve core vitals.
  • Lighthouse: a built-in Google Chrome tool, that allows you to analyze the quality of website pages. Among all metrics there are also CWV indicators in the Performance category.

Utilizing these tools will give you a clear picture of where your site stands and what steps need to be taken.

Strategies to improve Core Web Vitals

0. Define the problematic areas

Check your website with Core Web Vitals report to see which pages require your attention.

1. Optimize images and videos

  • Compression: Use modern image formats like WebP for better compression without quality loss. Optimize video sizes and use adaptive streaming.
  • Lazy loading: Implement lazy loading for images and videos to delay loading until they are in the viewport.

2. Enhance server response times

  • Reduce TTFB (Time to first byte): Choose a reliable hosting provider, use a CDN, and implement server-side caching to reduce TTFB.
  • Optimize server-side rendering: For dynamic content, consider server-side rendering or static site generation to improve loading times.

3. Minimize JavaScript execution

  • Code splitting: Break down your JavaScript into smaller chunks to reduce the amount of code loaded initially.
  • Defer unused JavaScript: Defer the loading of non-critical JavaScript to prevent it from blocking the rendering of the page.

4. Improve CSS performance

  • Minify and inline critical CSS: Minify CSS files and inline critical CSS to reduce render-blocking resources.
  • Reduce CSS complexity: Avoid overly complex CSS selectors and unnecessary styles that can slow down the rendering process.

5. Optimize web fonts

  • Font loading strategies: Use font-display: swap in your CSS to ensure text remains visible during font loading.
  • Limit font variants: Use only necessary font weights and styles to reduce the amount of data downloaded.

6. Ensure visual stability

  • Set size attributes for media: Always specify width and height attributes for images and videos to prevent layout shifts.
  • Use transformations: Prefer CSS transformations and animations over layout-affecting properties to ensure smooth animations.

Future-proofing your website

Google improves their algorithms every day, so if you want to stay ahead – you need to provide your online visitors with good performance. Regularly monitor your website’s score using the tools mentioned above and keep up with the latest best practices. Engaging with web development experts who specialize in core vitals can also ensure your website remains optimized for both current and future standards.

Conclusion

Improving Core Web Vitals is crucial for delivering a high-quality user experience and achieving better search rankings. By focusing on key areas such as image optimization, server response times, JavaScript execution, CSS performance, and visual stability, you can significantly enhance your website’s performance. As we move through 2024, make sure to prioritize these metrics to stay competitive in the digital landscape.

By implementing these strategies, you’ll not only improve core web vitals but also create a faster, more responsive, and visually stable web experience for your users.