Core Web Vitals, introduced by Google in 2020, are key metrics that measure various aspects of web page performance, including loading speed, interactivity, and visual stability. This matters because page speed and user experience directly impact user engagement, conversion rates, and search engine rankings. By analyzing how well web pages perform for real users, website owners and developers can identify areas for improvement and enhance the user experience.
The three Core Web Vitals metrics are:
1. Largest Contentful Paint (LCP) – measures the loading performance of a page, specifically the time it takes for the largest element on the page (such as an image or text block) to become visible to the user.
2. First Input Delay (FID) – measures the interactivity of a page, specifically the time it takes for the page to respond to the first user input, such as a click or tap.
3. Cumulative Layout Shift (CLS) – measures the visual stability of a page, specifically the number of unexpected layout shifts that occur during the page load, which can cause elements to move around and frustrate users.
Figure 1: Core web vitals metrics
These metrics are combined to calculate the performance score, with a good score ranging between 90-100. In addition, Google uses these metrics as part of its algorithm for ranking search results and has indicated that Core Web Vitals will become a more important factor in search rankings. Therefore, website owners and developers must optimize their pages to ensure the best possible user experience.
A few tools to measure are PageSpeed Insights, Chrome UX Report, Search Console and Lighthouse.[jb1]
Several examples of companies that witnessed a massive reduction in bounce rate and increase in impressions, time spent on site and conversion rate after implementing Core Web Vitals exist. For example:
• Tokopedia: 55% better LCP, 23% average session duration and 15% more time spent
• Vodafone: 31% better LCP, 15% better lead, 11% better cart-to-visit rate and 8% more sales
• GEDI: 77% CLS, reduced bounce rates by 8% on their mobile article pages
• NDTV: 50% less bounce rate
• Nykaa: 28% more organic traffic from Tier 1 and 2 cities after a 40% improvement in LCP.
By optimizing for Core Web Vitals, developers can confidently aim to deliver a better user experience by addressing the metrics with the most influence on the experience. It is particularly important because they reflect user-centric metrics that directly impact user satisfaction and engagement.
In conclusion, businesses must invest time and effort in optimizing for this set of metrics to improve overall website performance and ensure a high site ranking.
References: Introducing Web Vitals: essential metrics for a healthy site
