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.
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.