At the end of August 2021, Google finished rolling out significant changes to its search algorithm. The ‘page experience update’ sends a clear message to all that it’s time to fix the technical issues that hinder on-page user experience. The cleverest copy, visuals and features are no use if they don’t load super quick, in a way that makes sense across a range of devices, and support smooth and speedy interactions.

The search giant previously put technical performance on the agenda when it added mobile friendliness to the equation in 2015. But 2021’s update moves technical SEO up a gear. Sites that don’t get to grips with the common gripes of users when interfacing with pages may find themselves with a lower search ranking.

The page experience update presents new ways to measure page loading performance and stability. It introduces three new metrics – ‘Core Web Vitals’ – namely Largest Contentful Paint, First Input Delay and Cumulative Layout shift. Or LCP, FID and CLS, if you’re a fan of acronyms. You can check these and see what needs improvements on Google’s page speed insights.

Let’s take a closer look at the three Core Web Vitals, some of the common issues they present, and pointers on keeping scores healthy.

Largest Contentful Paint (LCP)

This new metric measures the time a website takes to show the user the largest content on the screen, complete and ready for interaction. It considers images, videos and text that appear above the page fold – the area that can be seen without scrolling. LCP helps developers consider page loading performance from the point of view of the user. For example, you may have a video at the top that is key to understanding the page, but takes several seconds to load. And when visitors are left looking at a white space for too long, the bounce rate goes up.

Google’s algorithm requires that LCP is kept to 2.5 seconds or under to avoid negatively impacting page ranking.

There are a few ways to improve LCP such as:

  • Optimizing images sizes – always use the specific dimensions suggested by your hosting
  • Using a good hosting service
  • Avoiding using JavaScript to load images
  • Using an image CDN (content delivery network) service

First Input Delay (FID)

This metric measures responsiveness. Specifically, the time between a user’s first interaction with the page and when the browser can respond to that interaction. The user needs this to be quick. For example, having filled out an online form and submitted the information, nobody wants to be kept in limbo while the website processes the request. It’s an important metric as it can be the difference between capturing or losing a lead or sale.

You’re looking for a low measurement – ie. as short a delay as possible. Google’s algorithm considers FID of 100 milliseconds or less a good score. Above 300 milliseconds ranks as ‘poor’.

The good news is that most sites should be fine when it comes to FID. A study by Screaming Frog found that 99% of desktop and 89% of mobile URLs fell within the threshold, and that FID had less of a correlation with search ranking than other Core Web Vitals. Bad FID scores are most often linked to heavy JavaScript execution so be sure optimise and reduce the use of JavaScript where possible.

Cumulative Layout Shift (CLS)

This metric measures the movements of a page as new content – such as images or ads – come into play later than the rest of the page. We’re all familiar with rogue ads popping up and making us lose the thread of what we were reading, or even click on a button we didn’t intend to. CLS is there to help developers achieve visual stability for a better user experience. It calculates a score based on how much of the page is unexpectedly moving about, and how often. You want to have a CLS score of 0.1 or below, and as close to zero as possible.

While LCP and FID can be seen as enhancements of previous metrics, CLS is something new entirely. It is measured through the lifetime of the page, and rather than being measured in milliseconds it is a unitless number arrived at by complex calculations. A less well understood quantity, CLS has been causing trouble to a lot of sites in terms of rankings since Google’s algorithm rolled out.

Techniques to improve CLS involve setting aside the correct amount of space before additional content is loaded — whether that is media or JavaScript-injected content. To avoid unexpected shifts, it’s best practice to always set width and height attributes on images. It’s also a good idea to limit the use of transform animations as many of them will trigger layout changes.

Keeping real people happy is now the key to SEO

Will many sites be affected by the page experience update – must we all become slaves to the algorithm? Nobody can predict the precise impact, but it’s wise to get to grips with the above elements for the ongoing health of your website. It’s part of a broad shift towards prioritising the needs of human beings in real-life situations, rather than abstracted data sets. The update is the latest move in Google’s quest to give internet users the most relevant, helpful and user-friendly sites to choose from when they search. The algorithm is now so sophisticated that there are no shortcuts to high ranking anymore. SEO is best achieved by designing digital products that engage and entertain humans and support their decision-making processes.

If you’d like to chat about what Google’s page experience update means for your website, do get in touch.