Web Vitals

Christian Schreiber

Web Performance Consultant

Contents

What are Web Vitals?

Web Vitals are a comprehensive collection of metrics developed by Google to evaluate the performance and user experience on websites. These metrics are divided into two categories: the Core Web Vitals and other supporting metrics known as Web Vitals. While the Core Web Vitals focus on three key metrics, there are additional Web Vitals that provide deeper insights into the performance and interactivity of a website.

What metrics do the Core Web Vitals include?

The Core Web Vitals are the central metrics that directly measure the user-friendliness and performance of a website:

Largest Contentful Paint (LCP): Measures the loading time of the largest visible element on the page. A good LCP value indicates that the main content of a page loads quickly.
First Input Delay (FID): Evaluates the amount of time until the page responds to the first user interaction. A low FID value means that the page reacts quickly to user actions.
Cumulative Layout Shift (CLS): Measures the visual stability of the page by quantifying unexpected layout shifts. A low CLS value indicates that the content remains stable and does not suddenly shift.
These metrics are crucial for optimizing user-friendliness and play an important role in Google rankings.

What are the supplementary Web Vitals?

In addition to the Core Web Vitals, there are other Web Vitals that highlight additional aspects of the performance and interactivity of a website. These metrics can serve as a supplement or as proxies for the Core Web Vitals:

Time to First Byte (TTFB): Measures the time it takes for a browser to receive the first byte from the server. A fast TTFB value indicates a fast server response and is often an indicator of good server performance.
First Contentful Paint (FCP): Records the time until the first visible content is rendered in the browser. A fast FCP value means that the user receives visual feedback early on.
Total Blocking Time (TBT): Measures the total time in which the page is blocked by long-running tasks and cannot respond to user interactions. A low TBT value indicates that the page becomes interactive quickly during the loading process.
These complementary metrics provide deeper insights into specific areas of website performance and help diagnose and resolve issues not covered by the Core Web Vitals alone.

Why are Web Vitals important?

Web Vitals are critical to understanding and optimizing the user experience. The Core Web Vitals focus on the most important aspects of performance that directly influence user-friendliness. The additional Web Vitals provide further insights that can help to diagnose and resolve specific problems. Together, they help to make a website faster, more interactive and more stable, which in turn leads to a better user experience and higher visibility in search engines.

How do Web Vitals influence the Google ranking?

Google uses the Core Web Vitals as important ranking factors to evaluate the quality of the user experience on websites. Pages that perform well in these metrics are ranked higher in the search results as they offer users better performance. The complementary Web Vitals help to identify and solve deeper performance issues, which can also indirectly affect ranking position by improving the overall user experience.

How can Web Vitals be optimized?

Various optimization strategies can be used to improve Web Vitals. These are aimed at shortening loading times, improving interactivity and increasing the visual stability of the site.

How can the loading time be improved (LCP and TTFB)?

Server optimization: Use powerful servers and optimize the server configuration to shorten the time until the first byte is sent (TTFB).
Content Delivery Network (CDN): A CDN can help deliver content to users faster, improving both the load time of the largest visible element (LCP) and the time to first byte (TTFB).
Optimization of media: Compress images and videos to reduce file size and increase loading speed. This directly improves the LCP.

How can responsiveness be improved (FID and TBT)?

Reduction of JavaScript: Minimize the execution time of JavaScript to improve the response time of the page (FID).
Code splitting: Divide the JavaScript code into smaller, faster loading parts to reduce the blocking time during the loading process (TBT).
Browser caching: Use browser caching to load frequently used files faster and increase the responsiveness of the page.

How can visual stability be improved (CLS)?

Set fixed size attributes: Define fixed sizes for images and videos in advance to avoid sudden layout shifts.
Avoid dynamic content: Make sure that content that is loaded later does not suddenly change the layout.
Optimization of advertising: Place advertising in such a way that it does not shift the layout and keeps the content stable.

What are the most common challenges in optimizing Web Vitals?

Optimizing web vitals can be complex, as various technical factors need to be taken into account. Here are some of the most common challenges:

Why is large media content problematic?

Large images and videos can significantly increase the loading time and have a negative impact on the LCP value. You should compress this content and optimize its loading behavior to ensure that the main content of the page loads quickly.

How does JavaScript influence Web Vitals?

Excessive JavaScript can affect the response time of the page and lead to long blocking times, which worsens the FID and TBT value. It is important to load and execute JavaScript efficiently in order to maintain the interactivity of the page.

Why are layout shifts a problem?

Unexpected layout shifts can severely impair the user experience and worsen the CLS value. This often happens when content is loaded dynamically or when the size specifications for media are missing, which leads to sudden changes in the layout.

How can Web Vitals be monitored?

To ensure that your Web Vitals remain optimized, there are several monitoring and analysis tools that can be used:

Which tools are suitable for monitoring Web Vitals?

Google PageSpeed Insights: Provides detailed analysis of web vitals and suggestions for improvement.
Google Search Console: Enables the monitoring of Core Web Vitals and provides insights into the performance of your website.
Lighthouse: An open source tool for analyzing and optimizing web performance that provides deeper insights into various web vitals.

How often should Web Vitals be monitored?

It is recommended to monitor the Web Vitals regularly, especially after major changes to the website. This helps to identify potential problems at an early stage and constantly improve the user experience.

Conclusion

Web Vitals are crucial metrics for evaluating the performance of a website. The Core Web Vitals focus on the three essential areas of loading time, interactivity and visual stability. The complementary Web Vitals provide additional insights and help diagnose specific issues that can affect the user experience. By taking targeted measures to improve these metrics, website operators can make their pages more efficient and user-friendly. Regular monitoring and adjustment are the key to optimum long-term performance.

Professional optimization of website load time, Google PageSpeed Score and Web Vitals