Core Web Vitals: key metrics for page experience

Google emphasizes the importance of site speed and user experience with its Core Web Vitals. Announced on 5th of May 2024, these metrics are crucial for ranking as they evaluate the quality of user interaction on websites. The Core Web Vitals are essential for providing a good user experience. But why should you care? Faster websites are find better AND people tend to stay on your website more. See also the blog post "10 Reasons why a fast website matters".

What are Core Web Vitals?

Core Web Vitals are specific factors that Google considers essential for delivering a great user experience on the web. They include:

1. Largest Contentful Paint (LCP)

Largest Contentful Paint (LCP) measures loading performance. To provide a good user experience, strive to have LCP occur within the first 2.5 seconds of the page starting to load.

Why this metric?

LCP is important because it marks the point at which the main content of the page has likely loaded, providing users with immediate visual feedback that the page is loading.

Improvement categories

• Good (green): ≤ 2.5 seconds
• Needs improvement (amber): ≤ 4.0 seconds
• Poor (red): > 4.0 seconds

2. Interaction To Next Paint (INP)

Interaction To Next Paint (INP) measures responsiveness. To provide a good user experience, strive to have an INP of less than 200 milliseconds.

Why is INP important?

INP assesses how quickly the website reacts to user interactions, such as clicks, taps, and other inputs, ensuring that the site feels responsive and interactive.

Improvement categories

• Good (green): ≤ 200 milliseconds
• Needs improvement (amber): ≤ 500 milliseconds
• Poor (red): > 500 milliseconds

3. Cumulative Layout Shift (CLS)

Cumulative Layout Shift (CLS) measures visual stability. To provide a good user experience, strive to have a CLS score of less than 0.1.

Why is CLS important?

CLS quantifies how often users experience unexpected layout shifts. A low CLS ensures that the page is visually stable, avoiding frustration from content shifting around as it loads.

Improvement categories

• Good (green): ≤ 0.1
• Needs improvement (amber): ≤ 0.25
• Poor (red): > 0.25

Why are Core Web Vitals important for ranking?

Core Web Vitals are crucial because they directly affect the user experience. Faster loading times, quicker interactions, and visual stability all contribute to a more pleasant user experience, which in turn can improve search rankings, traffic, and conversion rates.

How do I measure Core Web Vitals?

Core Web Vitals can be measured using several tools:

Field Tools

• PageSpeed Insights - Shows real-world performance data and suggestions for improvement.
• Web Vitals browser extension - Provides real-time feedback on Core Web Vitals metrics in Chrome.
• Google Search Console (Core Web Vitals report) - Displays Core Web Vitals metrics for your site and identifies pages that need improvement.

Lab Tools

• Chrome DevTools - Allows developers to debug and improve site performance.
• Lighthouse - Provides a comprehensive audit of web pages with specific recommendations for improvement.

Conclusion

For search engines, delivering a high-quality user experience is paramount. Core Web Vitals are key metrics that help ensure a site's performance is up to standard. By focusing on LCP, INP, and CLS, site owners can improve their rankings and provide a better experience for their users. For more detailed information, visit the official Google documentation on Core Web Vitals.

Do not forget to checkout the blog post "10 Reasons why a fast website matters".

Test your old website's speed

Use the tool below to test your old website's performance with Google's PageSpeed Insights. Please note that it can take up to 1 minute to complete the analysis. The default analysis is set to "mobile" because most people tend to view websites on a mobile nowadays (you can switch to "Desktop" after analysis to see how your old website performs on laptops or pc's/desktops).