Optimizing for quality of user experience is key to the long-term success of any site on the web. Through our ongoing engagement and collaboration with millions of web developers and site owners, we’ve developed many helpful metrics and tools across Google to help business owners, marketers, and developers alike identify opportunities to improve user experiences. However, abundance of metrics and tools creates its own set of prioritization, clarity, and consistency challenges for many.
Today we are introducing a new program, include loading experience, interactivity, and visual stability of page content, and combined are the foundation of the 2020 Core Web Vitals.
- measures responsiveness and quantifies the experience users feel when trying to first interact with the page.
- , and have supporting lab diagnostic metric equivalents and tooling. For example, while Largest Contentful Paint is the topline loading metric, it is also highly dependent on (TTFB), which remain critical to monitor and improve.
Measuring Core Web Vitals
Our goal is to make Core Web Vitals simple and easy to access and measure for all site owners and developers, both across Google surfaces as well as within their own dashboards and tools.
for each Core Web Vital. To enable that, a number of browsers, including Google Chrome, support the current Core Web Vitals draft specifications: , and JavaScript library, which can be used with any analytics provider that supports custom metrics, or as a reference for how to accurately capture each of the Core Web Vitals for your site’s users.
// Example of using web-vitals to measure & report CLS, FID, and LCP. import {getCLS, getFID, getLCP} from 'web-vitals'; function reportToAnalytics(data) { const body = JSON.stringify(data); (navigator.sendBeacon && navigator.sendBeacon('/analytics', body)) || fetch('/analytics', {body, method: 'POST', keepalive: true}); } getCLS((metric) => reportToAnalytics({cls: metric.value})); getFID((metric) => reportToAnalytics({fid: metric.value})); getLCP((metric) => reportToAnalytics({lcp: metric.value})); |
In our testing and development process we’ve found it valuable to have easy access to the state of each Core Web Vital both in development and as we browse the web. To help developers spot optimization opportunities today we are also releasing a developer preview of the , , and subscribe to our mailing list for future updates on vitals and all things Web.
Ilya Grigorik, Web Performance Engineer
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