Story Based Question
You’ve been working hard on improving your website’s user experience, focusing on speed, responsiveness, and stability. But after hearing about Core Web Vitals, you wonder: What exactly are the key metrics that Google uses to measure user experience? You know that these metrics are important for SEO, but you’re not sure what exactly they are or how they’ll help you improve your site’s performance.
Exact Answer
The three main Core Web Vitals metrics are Largest Contentful Paint (LCP), First Input Delay (FID), and Cumulative Layout Shift (CLS). These metrics measure loading performance, interactivity, and visual stability.
Explanation
Core Web Vitals focus on the aspects of your website that directly affect user experience. Google uses these three key metrics to evaluate how well your site performs for visitors. Here’s a breakdown of each metric:
- Largest Contentful Paint (LCP): LCP measures the loading performance of your website. Specifically, it tracks how long it takes for the largest visible element (like an image or a large text block) to appear on the screen. A faster LCP means that users can see content quickly, which improves their experience.
- Recommended score: 2.5 seconds or less.
- First Input Delay (FID): FID measures the time it takes for your website to respond to a user’s first interaction, such as clicking a button or link. A low FID means your website is responsive and quick to react to user actions.
- Recommended score: Less than 100 milliseconds.
- Cumulative Layout Shift (CLS): CLS tracks how much the page layout shifts as it loads, which can cause elements like images, text, or buttons to move around unexpectedly. A low CLS score means your website is visually stable, preventing frustrating shifts that could cause users to click on the wrong elements.
- Recommended score: Less than 0.1.
These three metrics help ensure that your site loads quickly, responds fast to user actions, and remains visually stable—all of which contribute to better user experience and SEO rankings.
Example
Imagine you have an online store. Here’s how Core Web Vitals would apply to your site:
- LCP: When a visitor arrives on your homepage, it takes 4 seconds for the product images to load. This is too slow! By optimizing the images and using lazy loading, you reduce the LCP to 2 seconds, which provides a faster loading experience.
- FID: When a user clicks on a product, it takes 2 seconds for the page to load. This is noticeable, and you could improve this by reducing JavaScript or simplifying the page’s interaction. By improving FID, the page reacts almost immediately, enhancing user satisfaction.
- CLS: When the homepage loads, some of the images and buttons shift around, causing users to accidentally click on the wrong links. By setting specific size constraints for images and using better layout techniques, you eliminate these shifts, improving the CLS score.
By improving these three Core Web Vitals, you boost your website’s user experience, which can lead to higher search rankings and better customer engagement.