Core Web Vitals

Core Web Vitals (CWV) are key website performance metrics. They are included in Web Vitals, a larger collection of metrics created by Google to assess various elements of website performance and user experience.

CWV Metrics

Core Web Vitals measure three essential aspects of user experience: loading performance, interactivity, and visual stability. The metrics are stable and critical in understanding user behavior and are less exposed to frequent changes than other metrics. However, while they are stable, they are not permanent and may be replaced by other metrics if they prove more efficient in dealing with the same issue.

• Largest Contentful Paint (LCP) evaluates how fast a page's largest visible element, like an image or a text, loads and appears on the screen. A good LCP score ensures users see the main content quickly, reducing the perception of waiting. LCP focuses on elements most critical to user experience.
• Interaction to Next Paint (INP) measures the time between a user's interaction, such as clicking a button, and the visible response on the screen. INP can evaluate responsiveness for all interactions during the page's lifecycle, offering a broader view of interactivity. A good INP ensures users experience smooth and quick feedback, enhancing usability and engagement.
• Cumulative Layout Shift (CLS) focuses on visual stability by tracking unexpected layout shifts while the page loads. CLS is very helpful in analyzing user frustration caused by these shifts, which can lead to accidental clicks or a disrupted browsing experience. Maintaining a good CLS score is essential for creating a seamless and stable visual environment.

CWV Scores

Largest Contentful Paint (LCP)

Interaction to Next Paint (INP)

Cumulative Layout Shift (CLS)

CWV Purpose

Core Web Vitals aim to make browsing websites more enjoyable for users. By following guidelines that promote a great user experience, websites benefit as users are more likely to explore further and return.

Core Web Vitals focus on:

• Improving loading time: pages that load quicker feel more efficient, giving users quick access to content and reducing frustration.
• Creating smooth interactions: ensuring pages respond instantly to actions like clicks or typing makes the experience seamless.
• Stabilizing visual elements: reducing sudden layout shifts allows users to read and interact with the page without interruptions or accidental clicks.

FAQ

Why Are Core Web Vitals Important?

CWV are critical indicators that monitor how fast the website loads, how responsive it is, and how stable the content is during the loading process. Improving these indicators is essential for enhancing user experience and encouraging users to stay on the page longer. CWVs are crucial for SEO best practices as search engines favor websites that provide a smooth and practical user experience.

Are Core Web Vitals a Ranking Factor?

Core Web Vitals are a ranking factor in Google’s search algorithm. Along with other elements, like content quality and mobile-friendliness, these metrics are essential to Page Experience Update. Websites that meet CWV standards deliver a fast, responsive, and user-friendly experience. Good CWV scores enhance the websites’ chances of ranking higher in search results.

How to Check Core Web Vitals?

According to Google, CWV are best measured using field data, reflecting how users experience the website in real-world conditions. Lab-based tools help identify potential performance issues and provide recommendations but don’t fully represent the user experience. For accurate field data measurements, Google recommends tools such as Chrome User Experience Report (CrUX), PageSpeed Insights (PSI), and Search Console. For lab data, Lighthouse and Chrome DevTools are widely used. Wattspeed uses both RUM and synthetic data to monitor website performance during the development process and after launch.

• Check Core Web Vitals workflows with Google tools.

How to Improve Core Web Vitals Score?

Optimizing the three Core Web Vitals metrics is essential for improving their score. Each CWV metric has recommendations that aim to enhance website performance.

• Largest Contentful Paint (LCP)

Google recommendations for improving LCP:

• Ensure the main LCP resource is identified in the HTML and prioritized for fast loading.

• Implement a CDN to improve server response times (TTFB).

• Focus on enabling quick and seamless page navigation.

• Interaction to Next Paint (INP)

Google recommendations for improving INP:

• Break up lengthy tasks by yielding frequently.

• Minimize extensive rendering updates.

• Eliminate any JavaScript that isn’t necessary.

• Cumulative Layout Shift (CLS)
  Google recommendations for improving CLS:

• Define specific sizes for all content loaded on the page.

• Avoid animations or shifts that trigger layout changes with CSS.

• Assure pages are compatible with the browser's back/forward cache (bfcache).

• Check the most effective ways to improve Core Web Vitals from Google.