%% date:: [[2023-01-20]], [[2023-04-26]], [[2023-04-30]], [[2023-04-30]] parent:: [[Frontend performance testing]], [[Google Web Vitals]] %% # [[Core Web Vitals]] [site](https://web.dev/vitals/#core-web-vitals) Core Web Vitals are an opinionated list of metrics, curated by [[Google]], that together represent the most important quantitative measure of [[User Experience]]. It is currently comprised of three metrics, each of which measures an important aspect of [[Frontend performance testing|frontend performance]]: - *Loading*: [[Largest Contentful Paint (LCP)]] - *Interactivity*: [[First Input Delay (FID)]] - *Visual stability*: [[Cumulative Layout Shift (CLS)]] ![[core-web-vitals.png]] [^webdev] Google goes as far as to say that "all site owners" should measure these three. Google also recommends that we measure the 75th percentile for all three metrics. [^webdev] These metrics should be measured for both mobile and desktop devices. The Core Web Vitals are a subset of the [[Google Web Vitals]]. <iframe width="560" height="315" src="https://www.youtube.com/embed/uERQXeWVV_E" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe> ## Tools Core Web Vitals are measured by the following tools. - [[Chrome DevTools]] - [[Lighthouse]] - [[k6 (tool)|k6]] with the [[k6 browser|k6 browser module]] [^webdev]: Google. *Core web vitals*. Retrieved on January 20th, 2023, from https://web.dev/vitals/#core-web-vitals