Web Performance – What, Why, How of Core Web Vitals

24 May 2021
Web Performance – What, Why, How of Core Web Vitals

Optimising and regularly Testing your website is a critical function for keeping your online presence fresh and relevant. But have you ever considered how we measure how well your website is performing, and how we can keep a finger on the pulse of that performance over time?

What are Core Web Vitals?

Google’s ‘Core Web Vitals’ is an initiative designed to do just that. By looking at three different aspects of your website’s performance – loading, interactivity and visual stability – Web Performance Testers can ensure the metrics you need to hit, are hit predictably and consistently.

There are three specific metrics we use to track Core Web Vitals:

  • Largest Contentful Paint measures how quickly your website loads, with a target of 2.5 seconds considered optimal.
  • First Input Delay measures user experience through interactive speed, with a target of under 100 milliseconds considered optimal.
  • Cumulative Layout Shift measures how consistent your websites visuals are maintained, with a target of 0.1 considered optimal.
How are Core Web Vitals measured?

There are several tools we use to measure Core Web Vitals, some developed and provided by Google, and others built in open source and the proprietary Web Performance tools we use on a regular basis for other Testing functions. These include the Chrome User Experience Report, PageSpeed Insights and Search Console’s Core Web Vitals report.

Each of these tools test all three Core Web Vitals markers, so you’re never left short in one or more Web Performance areas. Core Web Vitals can also be measured using standard Web APIs in Javascript, which means they can be integrated into a Test Automation Framework that your Testing partner should provide.

Why are Core Web Vitals important?

As long as we’re tracking these metrics and your website is regularly hitting its targets, all is well – at least as far as Web Performance is concerned. Should any of the metrics drop below target, we’ll be able to quickly note and assess the reasons, and take steps to correct them.

It’s important to not only take regular measurements of your Core Web Vitals metrics, but also regularly optimise all three areas, otherwise you risk performance issues affecting your online presence and overall business performance.

Bruce Zaayman
About Bruce

Bruce has over 17 years of consulting experience in performance and non-functional testing. The technical and analytical ability of the teams he’s built allows him to architect technical testing solutions for clients across a variety of industries, including retail, legal, banking, insurance, pharma and mining. Bruce has built strong partnerships with industry vendors, and worked with various international clients in structuring and implementing testing solutions within multi-supplier programme environments. He holds a B.Sc. Honours in Financial Mathematics and various other certifications.

Bruce Zaayman

Sales Director

Bruce is an Expert in Performance, Automated, and Functional Software Testing solutions and has been with Inspired Testing since its inception in 2016. He is based in London, UK, but used to serve as the Practice Head: Quality Assurance for DVT in Gauteng.

Bruce was part of the pioneering team that spearheaded DVT’s international expansion into the UK, shortly after which Inspired Testing was launched. His expertise allows him to provide clients with excellent testing solutions that integrate frictionlessly into their existing business processes.

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