Introduction:

The Guide to Core Web Vitals

October 5, 2021
5 min read

The Guide to Core Web Vitals

We want instant gratification when we search the internet. Google is constantly improving its search algorithms to deliver on that expectation.

Google’s challenge is forcing content creators to produce high-quality content instead of techniques to trick the search engine. With each monthly algorithm improvement, the search engine inches closer to better interpreting our search intent and matching it to the best available content.

Below are a few of the more than two hundred signals that help the search engine do just that:

  • Website’s reputation: Do reputable websites link to the one hosting the content?
  • Relevance: Are the titles, headings, and content related to the search?
  • Freshness: How recent is the content?
  • Length: How deep is the content?
  • Backlinks: Do other relevant articles link to the page containing the content?
  • User Engagement: How long do readers stay on the page?
  • Navigation: Is the website easy to navigate?
  • Mobile-friendly: Are the pages easy to read on a variety of mobile devices?
  • HTTPS: Are the pages secure by having valid security certificates?

Between June and August of 2021, Google introduced a few more signals collectively known as “page experience” to the existing long list of signals. 

The rationale behind this addition is to find the answer to the following questions:

  • Loading: Does the page load fast or leave searchers waiting?
  • Interactivity: Does the page respond quickly to user clicks upon loading?
  • Visual Stability: Does the content jump around as it loads, or is it stable?
The contributors to the page experience signal (source)

The technical names for the core web vital signals are: 

  • Largest Contentful Paint (LCP) for measuring the loading speed
  • First Input Delay (FID) for scoring interactivity
  • Cumulative Layout Shift (CLS) for calculating the visual stability
The Core Web Vitals components (source)

We created this guide to help website developers, performance engineers, and technical SEO specialists with the following:

  • Explain each concept in detail 
  • Provide the best tools and instructions for measuring the core web vitals 
  • Help readers improve the core web vital scores of their web pages


We also introduce three other web page measurements beyond the core web vitals (chapters four to six listed below) because website developers and SEO managers often reference them. 


Chapter 1: Largest Contentful Paint (LCP)

Chapter 2: First Input Delay (FID)

Chapter 3: Cumulative Layout Shift (CLS)

Chapter 4: Total Blocking Time (TBT) 

Chapter 5: Time To Interactive (TTI)

Chapter 6: First Contentful Paint (FCP)