A Technical SEO Guide From Semalt To Advanced Сore Web Vitals

As SEO professionals, we must be able to diagnose and provide solutions for our clients so we can deliver a better user-centric experience on their websites. Here, we will be showing you how we can improve your Core Web Vitals (CWV). 

Every client that walks in our doors expects us to deliver a good web experience for their users. But do you know what that looks like in practice? A recent study that was cited by Google displayed some interesting facts about CWV. From that post, we learn that mobile web users keep their attention on the screen for approx. 4-8 seconds at a time. Which makes things extremely difficult for us as professionals. 

What we understood from that post is that we have less than 8 seconds to give a mobile phone user at least one reason to stick around that content. In less than 8 seconds, we must be able to deliver interactive content and get a user to complete a task. 

Core Web Vitals

A website's core web vitals are three metrics that have been designed to measure a site's performance from the perspective of a human user. In early May 2020, the Open-source Chromium project announced its metrics updates, which were quickly included in Google's products. 

How can we qualify performance from the perspective of a user? To answer this question, you must be able to answer these three questions:
  1. Is it loading?
  2. Can a user interact with it?
  3. Is it visually stable?
Fundamentally, CWV was designed to measure how long a webpage takes to complete the script functions needed to create the above-the-fold content. When a page passes CWV assessments, its users are 24% less likely to abandon the page loads. These efforts mostly benefit the humans who use your site. 

Page Experience Update

Regardless of all the buzz, CWV is like another element in the ranking signal. Starting in mid-June, we should see it rolled out gradually all through August 2021. Page experience rankings will comprise of: 
  1. Core web vitals
  2. Mobile friendly
  3. Safe browsing 
  4. HTTPS 
  5. No intrusive interstitials 
Recent documentation clarifies that the rollout will be gradual, and sites should worry about falling victim to sudden drastic changes. 

Here is a break-down of the important things you should know about this update:

New page Experience report in the Search console

The Page Experience Report will now be included in Search Consoles. This fresh source of information includes saved data that goes as far back as 90 days. For a URL to be considered good, there are certain criteria it must meet.
The new report, which is expected to roll out, offers a high-level widget that links to reports for each of the five criteria that make a URL good. 

Workflow for Diagnosing and Actioning CWV Improvements

First, we should break down the meaning of Field and Lab data.

Field Data is performance data that is collected from real page loads which your real website visitors are experiencing on their browsers. Field data is sometimes called Real User Monitoring. These two terms mean the same thing. 

New Core Web Vitals assessments and the Page Experience Ranking signals will harness the information contained in the Field Data report that is collected from the Chrome User Experience Report. 

Which users are part of the Chrome User Experience Report? 

Crux data is fundamentally aggregated for users who meet three criteria, namely:
  1. The user has set up a Sync passphrase.
  2. Users opted-in to syncing their browser history to their email address. 
  3. The user has enabled usage statistics reporting.
In the world of Core Web Vitals Assessment, Crux is the ultimate source of truth. Crux data can be accessed using PageSpeed Insights, Google Search Console, an origin-level dashboard in Google Data Studio, or even Public Google BigQuery project. 

Clients wonder why we need all of this; well, the answer is CWV Field Dara is a restricted set of metrics that has limited debugging abilities and requirements for the availability of its data. 

Why wouldn't some pages have the data available from Crux?

When running diagnostics on certain pages, we may discover that the Chrome Experience Report lacks sufficient real-world speed data for certain pages. What this means is that the page doesn't have the data available from Crux because the Crux data has been anonymized. For this data to be displayed on the page, there must be enough page loads to report without any chance of the user getting identified. 

Web Core vitals are best identified using the Real User Monitoring data and then diagnosed using the lab data. 

Lab Data allows us to debug performance with in-depth visibility and end-to-end into the UX. As the name is "lab," the data is collected in a controlled environment with already predefined conditions, devices, and overall network settings. Lab data can be gotten from the web.dev/measure, PageSpeed insights, Chromium-based crawlers like Deepcrawl or NodeJS Lighthouse, or Chrome DevTool's Lighthouse panel. 

The Workflow process

1. Identifying the issues with crux data: 

For this, we start with the Search Console's core web vitals report to identify what group each page falls into and if they need attention. We harness the information seen in the Crux data and uses it to further by pairing similar URLs together. An example of such pairing will be based on the behavioral patterns of these URLs. With this process, solving the root issue for one page will most likely fix the problem in all the pages that share the CWV issue. Our pro-tip at this stage is to focus on Mobile data. This is particularly important as Google has begun tilting towards a Mobile-First indexing system, and Core Web Vitals will most likely influence the SERPs on mobile devices. Finally, we prioritize our efforts based on the number of URLs impacted. 

2. Using the page speed insights to combine the Lab and field data: 

Once we've identified the pages we will need to work on, we use page speed insights which are powered by Lighthouse and Chrome UX report to run an analysis on the lab report and find any lingering issues on the page. Note that lab tests are one-off emulates tests which means one test alone isn't 100% true, and neither will it provide a definitive answer. The key to getting an accurate reading is to test multiple example URLs. Page speed insights can only be used to test publicly available and indexable URLs. 

3. We create a ticket: 

As SEO professionals, we stay actively involved in the ticket refinement and QA processes. Our development team works in sprints. For each sprint, a set of tickets are formed. These tickets aid our development team to size the effort better and get those tickets into sprints. 

4. Q4 Changes in staging environments using Lighthouse: 

Before we push any code into production, we place it in a controlled staging environment for observation and testing. Lighthouse is an excellent means to measure CWV. In our article on a technical SEO guide to Lighthouse metrics, we highlighted how we could use this tool for many things as well as how we use it. Note that a lower environment will have fewer resources, so we rely on an acceptable criterion to hone in on whether the development work completely met the task given. 


Google plans on updating its Page Experience Component on an annual basis which means we should expect more CWV rollouts. Imagine the benefits SEO professionals and our clients will enjoy if we get notified in advance of new vital updates in SERP. 

As technical SEO pros, we are more equipped to diagnose and provide solutions for a better user-centric experience. With our help, the ROI can be found in every channel so your business scales. Your organic performance is an overall reflection of how good a site is. We will help you leverage this position as we continue to optimize your site for SEO. 

Interested in SEO? Check out our other articles on the Semalt blog.