The quality of the page experience depends on several factors. But Core Web Vitals bring together the
main elements of the page loading experience as the user accesses and interacts with its elements.
Below we’ll go into more detail about each Core Web Vitals metric. Read on!
Largest Contentful Paint (LCP)
Largest Contentful Paint or LCP is the telegram number list metric that measures the speed at which
the page fully loads its content for the user.
It can be translated as ” the best content impression “. This metric replaces other indicators used
until now, such as First Contentful Paint (FCP), which measures only the loading of the first page
element, and First Meaningful Paint (FMP), which focuses on the main page element, but tends to be
inaccurate.
So LCP measures loading speed by render time, up to the point when your largest element (image, video, or text) appears on the screen for the user, assuming it’s the main content of the page. This can be influenced by server time , CSS , JavaScript , and other factors.
Google recommends that Largest Contentful Paint stay below 2.5 seconds, which is considered a satisfactory limit for websites and capable of providing a satisfactory user experience.
Between 2.5 and 4 seconds, the page needs adjustments. Above 4 seconds is a sign that you may be losing a lot of visitors.
First Input Delay (FID)
First Input Delay or FID is the metric communication: the strategic asset we can no that measures the speed of response to the user’s first interaction with the page, such as a click or a JavaScript control.
It can be translated as “ first input delay .” This means that FID measures the time from when the user first interacts until the site can process a response to that interaction, which occurs in milliseconds. This delay or input latency can be caused by other processes, such as loading a large JavaScript file in parallel.
Google understands that a user’s impression of a site is determined not only by the loading of the content, but also by the response time. Therefore, it is important to combine the evaluation of LCP and FID, not just one or the other.
The recommendation is that this time should not exceed 100 milliseconds, so that the user has a quick response and does not abandon the page. Between 100 ms and 300 ms, it is a warning sign for adjustment. Above 300, it is a bad experience.
Cumulative Layout Shift (CLS)
Cumulative Layout Shift or CLS is the shandong mobile phone number list metric that measures the frequency and severity of unexpected changes in a page’s layout. This expression can be translated as ” cumulative layout shift “.
These unexpected changes occur when an element on the page changes location while the user is interacting with the page. This happens, for example, when you are going to click on a button, but an element loads and changes the position of that button, causing you to click where you don’t want to. This can be extremely irritating and even create problems for the user.
This is usually because page elements are loaded asynchronously or have some dynamic configuration to adapt to the context. So, heavier elements, unsized images , or automatically resized ads can cause sudden movements that disrupt the on-page experience.
To measure this, Google establishes a layout shift score. The score is the result of multiplying the Impact Fraction, which measures how the unstable element impacts the display, and the Distance Fraction, which measures how much the element has moved in the layout.
Google recommends that your page’s CLS score be less than 0.1. Between 0.1 and 0.25, you need to make improvements. Above 0.25 means the user is having a bad experience with sudden page changes.
How to measure Core Web Vitals?
With the announcement of Core Web Vitals, Google also said it was adjusting its SEO tools to incorporate the metrics. Below, we’ll walk you through the main capabilities of the analytics tools.
It’s important to know that Core Web Vitals metrics can be measured in the lab ( lab data ) or in the field ( field data ). But what does that mean?
- Lab data: This means that the analysis uses tools that simulate the loading of a page in a controlled environment.
- Field data: This means that the analysis considers real user interactions and captures nuances that the lab doesn’t. This is what Google uses in its algorithm.
Therefore:
- FID is a metric that can only be measured in the field, as it requires a user to interact with the page. In this case, tools can use another metric (Total Block Time or TBT) to calculate the approximate FID.
- LCP and CLS can be measured both in the field and in the laboratory.
Each tool can use a different method and therefore produce different results. That’s why it’s important to know how each tool works and combine laboratory and field results to have a complete diagnosis. Let’s look at this below!
Chrome User Experience Report (CrUX)
The Chrome User Experience Report uses field data to analyze Core Web Vitals metrics, as well as other diagnostic metrics for pages.
You can access Chrome UX Report data in four ways:
- CrUX Dashboard , a customizable dashboard for your website in Google Data Studio;
- PageSpeed Insights , which pulls data from CrUX;
- CrUX in BigQuery , which requires SQL knowledge to perform advanced analysis;
- CrUX API , to integrate with data from other applications and customize analysis.
PageSpeed Insights
PageSpeed Insights is a tool traditionally used by websites to measure page speed . Now, it also reports Core Web Vitals metrics, split between desktop and mobile, as well as suggestions for improvements. It’s available on the web and as an API.
The tool gives us field data from Chrome’s User Experience Report. However, it also has lab data and an overall speed score that is based on Lighthouse analysis, another tool we’ll look at later.
