Definition: Core Web Vitals [CWV]

Core Web Vitals are a set of metrics introduced by Google in 2019 that were meant to become ranking factors for Google Search in 2020. There are three metrics included:

  • LCP (Largest Contentful Paint) – how long until the majority of the page loads
  • FID (First Input Delay) – how long until a page can be interacted with
  • CLS (Cumulative Layout Shift) – how much page content shifts after loading

These are an interesting set of metrics as they focus so intently on user experience. Google refers to these as being about loading, interactivity, and visual stability, but I would characterise the first two as being about page speed and the third one as not annoying your users.

A new section of Google Search Console has been added to help measure these Core Web Vitals, including three tiers of performance for each – Good, Needs Improvement, and Poor.



While a big deal has been made of these new ranking factors, they are not expected to be the dominant way in which web pages are measured in any sense. On top of that, measurement of all three of these metrics is generally considered to be quite harsh – with very few sites actually scoring good across the board.

I would highly recommend doing what you can to score well for all three of these metrics as they will create a better user experience which can have a positive knock-on effect. However, keep in mind that scoring perfectly on these metrics is no guarantee of ranking well on Google.

If you want more details, Google has a great page explaining everything here.



A blue rectangular image with a definition of Core Web Vitals on it, which reads: A set of 3 ranking factors for Google search. Two of them are types of page speed: LCP (Largest Contentful Paint) & FID (First Input Delay). CLS (Cumulative Layout Shift) is how much page content shifts after loading.

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