Core Web Vitals: The Unsung Hero of SEO That Could Make or Break Your Rankings


Core Web Vitals have emerged as a critical component of SEO, significantly impacting your website’s ranking potential. At Once Digital, we recognize that these metrics, often overlooked, play a pivotal role in ensuring your site delivers an exceptional user experience. In this post, we’ll explore what Core Web Vitals are, why they matter, and how you can optimize them to enhance your SEO.

Understanding Core Web Vitals

Core Web Vitals are a set of specific factors that Google considers essential for delivering a great user experience. These metrics focus on the loading performance, interactivity, and visual stability of your website. The three main Core Web Vitals are:

  • Largest Contentful Paint (LCP): Measures loading performance. LCP should occur within 2.5 seconds of when the page first starts loading.
  • First Input Delay (FID): Measures interactivity. FID should be less than 100 milliseconds.
  • Cumulative Layout Shift (CLS): Measures visual stability. Pages should maintain a CLS of less than 0.1.

Why Core Web Vitals Matter

Google uses Core Web Vitals as part of its ranking algorithm, emphasizing the importance of a positive user experience. Websites that score well on these metrics are more likely to rank higher in search results, whereas those that perform poorly may see a drop in rankings.

User Experience and Engagement

a laptop computer sitting on top of a table

A website that loads quickly, is interactive, and visually stable provides a better user experience. This not only helps in retaining visitors but also encourages them to engage with your content, reducing bounce rates and increasing time spent on the site.

Competitive Advantage

Optimizing Core Web Vitals can give you a competitive edge. Many websites still overlook these metrics, so focusing on them can set you apart and help you achieve higher rankings.

How to Optimize Core Web Vitals

1. Improving Largest Contentful Paint (LCP)

LCP measures how quickly the largest content element in the viewport loads. To improve LCP:

  • Optimize Images: Compress and properly size images to reduce load times.
  • Use a Content Delivery Network (CDN): Distribute your content across multiple servers to improve loading speed.
  • Minimize Render-Blocking Resources: Reduce the number of CSS and JavaScript files that block rendering.

2. Enhancing First Input Delay (FID)

FID measures the time from when a user first interacts with your site to the time when the browser responds. To reduce FID:

  • Minimize JavaScript Execution: Break up long tasks and optimize your JavaScript.
  • Use Web Workers: Run scripts in the background without blocking the main thread.
  • Optimize Third-Party Scripts: Limit the use of third-party scripts that can slow down your site.

3. Reducing Cumulative Layout Shift (CLS)

CLS measures the unexpected layout shifts that occur during the loading phase. To minimize CLS:

  • Specify Size Attributes: Set explicit width and height on images and video elements to reserve space.
  • Avoid Inserting Content Above Existing Content: Ensure ads and other dynamically injected content do not push existing content down.
  • Use CSS Transformations: For animations and transitions, use CSS transformations rather than properties that trigger layout changes.

Tools to Measure Core Web Vitals

Several tools can help you measure and optimize your Core Web Vitals:

  • Google PageSpeed Insights: Provides detailed reports on your Core Web Vitals and offers suggestions for improvement.
  • Lighthouse: An open-source tool that audits your web pages and highlights areas for optimization.
  • Web Vitals Extension: A browser extension that gives you real-time feedback on your Core Web Vitals.

Case Study: Optimizing Core Web Vitals with Once Digital

At Once Digital, we’ve helped numerous clients enhance their Core Web Vitals, leading to improved rankings and user satisfaction. Here’s an example of how we optimized Core Web Vitals for a Swiss retail client:

  • Image Optimization: We implemented lazy loading and compressed images, resulting in a significant reduction in LCP.
  • JavaScript Optimization: By breaking up long tasks and optimizing scripts, we reduced FID and improved overall interactivity.
  • Layout Stability: We addressed CLS issues by specifying size attributes and minimizing layout shifts, enhancing visual stability.

These optimizations led to a 30% increase in organic traffic and a 20% improvement in conversion rates, demonstrating the tangible benefits of focusing on Core Web Vitals.

For more insights on optimizing your website, check out our other articles:

Summary Table: Core Web Vitals Optimization Strategies

MetricOptimization ActionsDescription
Largest Contentful Paint (LCP)Optimize images, use CDN, minimize render-blocking resourcesImprove loading performance by ensuring the largest content loads quickly
First Input Delay (FID)Minimize JavaScript execution, use web workers, optimize third-party scriptsEnhance interactivity by reducing the time taken to respond to user inputs
Cumulative Layout Shift (CLS)Specify size attributes, avoid inserting content above existing content, use CSS transformationsMaintain visual stability by preventing unexpected layout shifts during page load


Core Web Vitals are crucial for ensuring a great user experience and achieving high search rankings. By understanding these metrics and implementing the recommended optimizations, you can significantly enhance your site’s performance and user satisfaction. At Once Digital, we’re committed to helping Swiss businesses navigate the complexities of SEO and improve their Core Web Vitals.

Focus on optimizing LCP, FID, and CLS to provide a seamless and engaging experience for your users. With the right strategies and tools, you can turn Core Web Vitals from an unsung hero into a cornerstone of your SEO success.

Scroll to Top