Core Web Vitals
· by the Agence Web Premium team, Guéliz Marrakech
Direct answer: Google measures three things: the speed of displaying main content, responsiveness to clicks, and visual stability. All three can be measured for free in thirty seconds, and the most effective corrections cost between 1,500 and 5,000 MAD.
Behind the acronyms, the three indicators describe a very concrete experience: is it displayed quickly, does it respond when I click, does it move under my finger.
LCP — does the main content display quickly?
In short: Goal: less than 2.5 seconds. This is the time it takes for the largest visible element to appear.
Concretely: the main image or title of your home page. If the visitor looks at a white screen for four seconds, they leave.
Common causes of poor LCP: unoptimized banner image, slow server, fonts that block display, or scripts loaded before content.
Most cost-effective fix: compress the main image, convert it to WebP, and load it with priority.
INP — does the site respond when clicked?
In short: Objective: less than 200 milliseconds. This is the delay between the visitor's action and the site's visible reaction.
This indicator replaced the old FID in 2024 and it is more demanding: it measures all interactions, not just the first.
Main cause of bad INP: too much JavaScript taking up the browser. Every library, every tracker, every widget adds load.
Correction: remove what is not needed, defer what is not necessary to the initial display, and avoid very heavy page builders.
CLS — does content move while loading?
In short: Objective: less than 0.1. It measures unexpected element movements during loading.
You know the experience: you go to click a button, an image loads above, everything goes down, and you click on an ad.
Causes: images without declared dimensions, dynamically inserted advertisements, fonts that change the size of the text, banners injected at the top of the page.
Simple and very effective fix: declare the dimensions of each image and reserve space for dynamically loaded elements.
How to measure for free?
In short: Google PageSpeed Insights, and the Essential Web Signals report in Search Console.
PageSpeed Insights provides two types of data: laboratory measurements, simulated, and field data, from real visitors over the last 28 days.
Rely on field data: this is what Google uses. A site can get a good simulated rating and poor real data if the audience is mainly on mobile on 4G.
Always test the mobile tab as a priority: in Morocco, this is the majority of traffic.
Do these indicators really change the ranking?
In short: Yes, but moderately. They decide between pages of comparable quality; they do not compensate for weak content.
Let's be honest: a great, slow page will often beat a mediocre, fast page. Core Web Vitals are not the dominant factor.
On the other hand, their effect on conversion is massive and immediate. A site that displays in one second instead of four keeps many more visitors — regardless of Google.
This is why we keep our pages under 100 KB: the argument is not SEO, it is the customer who does not leave.
The three indicators and their thresholds
| Indicator | What it measures | Good | To be corrected | Common cause |
|---|---|---|---|---|
| LCP | Showing main content | < 2.5 sec | > 4 s | heavy banner image |
| INP | Click responsiveness | < 200 ms | > 500 ms | too much JavaScript |
| CLS | Visual stability | <0.1 | > 0.25 | dimensionless images |
Official Google thresholds as of October 4, 2026.
Frequently asked questions
What are Core Web Vitals?
Three Google indicators: LCP (display speed), INP (click responsiveness) and CLS (visual stability).
How to measure them for free?
With PageSpeed Insights and the Essential Web Signals report from Search Console. Favor field data, mobile tab.
What is the correct LCP score?
Less than 2.5 seconds. Beyond 4 seconds, the correction is urgent.
Why is my INP bad?
Almost always because of an excess of JavaScript: libraries, trackers and widgets that take up the browser.
How to correct CLS?
Declare the dimensions of all your images and reserve space for dynamically loaded elements.
Do Core Web Vitals really influence rankings?
Moderately. They decide between comparable pages. Their effect on conversion, however, is very significant.
How much does optimization cost?
Between 1,500 and 5,000 MAD depending on the size. The diagnosis is free with us.
What weight are we aiming for for a page?
We keep our pages under 100 KB, compared to an industry average of over 2 MB.
Free Core Web Vitals Diagnostic
Send your address. We will send you back your three real scores and the two priority corrections.
