Core Web Vitals: What the New Google Metrics Mean for Your SEO Strategy [5 Reading Tips]

Google. The most popular search engine is constantly trying to improve its search results for users, for example with regular Google updates. It wants Internet users to be able to get information quickly and to have an overall positive experience on websites. That is why Google supports admins and content creators in improving their websites.

With the Core Web Vitals, Google has initiated such a measure to improve web content: uniform metrics for clear statements about the technical quality of a website. Those who run a website themselves and do not want to drop down in Google’s SERPs should make the Core Web Vitals part of their future SEO strategy.

Core Web Vitals – What Is It?

With the Core Web Vitals, Google introduces metrics that provide website operators with information on the quality of their web presences. However, it is not about the content on websites. The Core Web Vitals measure technical aspects that have an impact on the user experience. To be more precise: the metrics refer to the experience that website visitors have in the first few seconds. Google has defined three metrics for this:

Largest Contentful Paint, First Input Delay and Cumulative Layout Shift.

For the Core Web Vitals, Google captures the experience of website visitors. In order to measure this, Google evaluates data from the Chrome browser and uses it to create the Chrome User Experience Report. Mobile data and measured values from desktop PCs are specified separately here. In the report itself, you can always find an aggregated score that includes 75 per cent of website visits. This is important because different users sometimes have completely different experiences. Ideally, however, websites should be designed in such a way that all users have a positive experience.

Core Web Vital 1: Largest Contentful Paint (LCP)

How quickly can users see content on the website? Google uses LCP to measure when the largest visible content block (in terms of visual presentation) is displayed to users. This can be text, images or videos, for example. Since the largest element is usually loaded at the end and is likely to be the main content of the page, this allows Google to get a pretty good idea of how long it takes until users can read the website or interact with it in the first place.

With LCP, the search engine company has developed an alternative to older metrics such as Load or DOMContentLoaded. These metrics tend to provide information that is of a theoretical nature, while Largest Contentful Paint is much more focused on the actual user experience. The very similar First Contentful Paint (FCP) metric, in turn, only indicates how quickly the first element was loaded. In many cases, however, this is completely irrelevant for the actual content of the website. After all, the First Meaningful Paint (FMP) metric proved to be too complex and error-prone.

As a benchmark, Google states that the Largest Contenful Paint should appear to users within 2.5 seconds of the page starting to load. It is important that this benchmark applies to all users. Results that webmasters achieve in tests can differ greatly from the experiences of different users.

The LCP score can be improved by

using a framework instead of an HTML page
reducing the size of images
using a content delivery network

Core Web Vital 2: First Input Delay (FID)

Once the website has been loaded, users want to interact with it. First Input Delay indicates how long it takes for a website to react to the first user interaction. This can be a login attempt, for example, but also a simple click on a link. In order not to spoil the first impression, servers should process the input as quickly as possible. However, server speed is only part of the challenge of achieving a good FID score: webmasters should also take users’ browsers into account. If the software has to deal with other tasks, it cannot process input. Therefore, large JavaScript files that keep browsers busy for a long time are the most common weakness.

Google states that it should take about 100 milliseconds from the moment a user triggers an interaction until the change becomes visible in the browser.

The FID score can be improved by

avoiding processing times of more than 50ms
loading the most important interaction elements first
using web workers

Core Web Vital 3: Cumulative Layout Shift (CLS)

Websites are often loaded in such a way that visitors can already use them before the last element appears in the browser. This offers great advantages in terms of LCP, but can cause substantial layout shifts. Content elements jumping around, however, result in users either getting confused while reading or unintentionally clicking on the wrong element.

For the CLS score, Google measures the changes to the layout of a page. Every time an element unexpectedly changes its position is recorded. Intentional changes caused by user interactions are thus excluded. Not only does Google pay attention to how many elements are shifted how often, but it also measures how far they move. All of this is included in Cumulative Layout Shift.

Google considers a CLS score of 0.1 to be good. If websites are significantly above this threshold, they should be optimised.

The CLS score can be improved by