According to Google research, 54% of mobile users say that as loading time increases, so does their level of frustration. Increasing your website visitors’ frustration level doesn’t pay; Google also reports that making a user wait for just 1 additional second can impact conversion rates by up to 20%.

Can you afford to neglect performance, health and, thereby, user experience? BMW didn’t think so when creating its new mobile site.

BMW focussed on speed, ruling out any feature that would slow down the site and hinder its performance and on-page experience. Their new mobile site ended up being 4 times faster than their previous site, leading to 4 times as many users clicking through from their main site to a sales site.

Google itself also rewards faster sites - mobile site speed is a component of quality score, which determines the position and price of search ads. Moreover, Improving site speed will lead to more organic traffic - in the case of BMW, their new site delivered a 49% increase (!).

Clearly, considering and improving the speed of your website is worthy of your time. But, of course, it’s not that simple; there are so many factors that influence site speed, and even a number of metrics used to measure the speed/health of any given site. Enter Web Vitals.

For best-practice advice about how and why to improve the speed of your website, click here. Or to get a bit more technical, you can put these five tips into action...

Introducing Google Web Vitals

What Google looks for in terms of website performance hasn’t always been clear. So, in an “attempt to simplify the landscape, and help sites focus on the metrics that matter most,” it has released its Core Web Vitals - “essential metrics for a healthy site”.

These Core Web Vitals focus on three key metrics when assessing the quality of a site’s user experience, and this will likely start impacting how much advertisers pay for clicks to these sites, as well as organic performance.

Google has doubled down on these metrics, incorporating them as a key part in Google tools already being used to measure website performance, such as PageSpeed Insights and Search Console, as well as the new Web Vitals Google Chrome extension.

Moreover, according to Google "the metrics that make up Core Web Vitals will evolve over time. The current set of vitals for 2020 focuses on three aspects of the user experience—loading, interactivity, and visual stability..." Let's dig into these metrics a little more.

The Core Web Vitals

The three metrics they focus on are “Largest Contentful Paint” - a measure of site speed - “First Input Delay” - a measure of interactivity - and, finally, “Cumulative Layout Shift” - a measure of visual stability.

While Largest Contentful Paint (LCP) is the metric that is most obviously impacted by changes to site speed, as it’s pretty much a direct measure of site speed, measuring how long it takes for the largest piece of content to load on your page, the other two metrics are also negatively impacted by a slow site.

First Input Delay (FID) refers to how long it takes for the browser to respond to the first request of the user on a page; clicking on a button or using an interactive element, for instance. A common reason that this could be slow is if the page hasn’t finished loading yet and the main thread is busy. Therefore, improving your site speed will make it more likely that the main thread is empty by the time the user decides to interact with your site.

Cumulative Layout Shift (CLS) refers to how elements on the screen move on the page. These can be split into 2 categories; those prompted by the user, and those unprompted by the user. If the user clicks a button to open a piece of content or a drop-down menu, they are expecting an element to move, this is often part of a good experience.

Whereas if elements on the screen move unexpectedly - without user input - it is usually negative for the user experience, and Google will penalise you for this by giving you a worse CLS score.

The way that Google decides if an element moving was prompted by the user or not is by measuring whether there was a user interaction in the 500 ms (half a second) before an element moved.

Unfortunately, this also means that if the user interacts with your page and it takes more than half a second to process and have the visual change take place, Google will assume it’s unexpected and penalize your site. It’s therefore key that changes on-screen happen as fast as possible.

Measuring Core Web Vitals

Of course, none of this information would be particularly useful if there weren’t an easy way to measure and understand your performance across the Core Web Vitals. Happily, Google knows its onions, and you can use its Chrome User Experience Report to gain a quick overview of performance.

Having said that, a simplified overview often isn’t enough to diagnose and fix a problem. So Google has put together a short guide about how you can start measuring these Web Vitals on a “per-pageview” basis.

Final Thoughts

The importance of website speed in 2020 cannot be overstated, and Google introduction of its Web Vitals only serves to emphasise that. And it’s inconceivable that site performance, health and UX won’t continue to increase in importance next year and far beyond.

Though you’ll all be capable of using the Chrome User Experience Report to unlock valuable information about your own website’s performance against Google’s Core Web Vitals, going beyond that requires a little more specialist knowledge.

If you’re in need of help to properly diagnose, measure and fix problems with the health of your website, please don’t hesitate to get in touch >>>