Understanding LCP: a key factor in SEO

Through our SEO Agency Optimize 360

on the theme : Technical SEO

Le Largest Contentful Paint (LCP) has become one of the key elements in assessing the quality of a website and its performance in terms of natural referencing.

LCP measures the time taken to display the main content of a page, which allows search engines such as Google to judge whether your site provides user experience pleasant or not.

The purpose of this article is to introduce you to the main features and definitions LCP in the field of Search Engine Optimization (SEO).


What is Largest Contentful Paint (LCP)?

LCP is one of the Core Web VitalsLCP is a set of metrics developed by Google to analyse the loading, interaction and stability performance of a website. More specifically, the LCP measures the time taken for the browser to render the largest element of a website. visible in the display window when a page is loaded.

It is important to note that not all elements are taken into account for this measure; only those considered essential for the user experience are concerned, such as :

  • Images (including those used in the background via CSS)
  • Videos (with visible dimensions)
  • Text blocks (such as paragraphs or headings)

Other important SEO measures

Although the LCP plays a crucial role in evaluating a page, other performance indicators such as :

  • Le First Contentful Paint (FCP)which measures the time taken to display the first item of content on a page.
  • Le Time to Interactive (TTI)which measures the time before a user can fully interact with the page.
  • Le Cumulative Layout Shift (CLS)which quantifies unexpected changes to the page design during loading

Why is LCP important in SEO?

With the advent of Core Web Vitals, Google is placing greater emphasis on user experience to improve its ranking in organic search results. As a result, optimising the LCP can result in better visibility in the SERPs and, potentially, an increase in organic traffic.

What's more, a good LCP score helps to ensure a smooth and pleasant user experience for visitors to your site.This can also have a positive impact on the conversion rate, average visit duration and even customer loyalty.

How to optimise your site's LCP

To ensure that your pages load quickly and provide an optimal user experience, there are a number of best practices that can be put in place:

Minimise server requests

The number of HTTP/HTTPS requests between the client and the server has a direct impact on the loading speed of a page. The more of them there are, the longer it takes to display all the content.

To reduce these requests, solutions such as concatenation of CSS and JavaScriptthe creation ofunified SVG icons or the use ofresponsive images can be implemented.

Compressing and optimising images

Images often make up a large proportion of the total weight of a page. To improve their loading time, we recommend :

    • Use appropriate formats (JPEG 2000, WebP)
    • Optimising their dimensions
    • Apply lossless compression to reduce their size without compromising their quality

Setting up an effective caching system

The cache allows resources (CSS files, scripts, images) to be stored locally so that they can be loaded more quickly on subsequent visits.

Consequently, the use of a plugin or appropriate parameters in your server can significantly improve the LCP.

These three approaches represent just a sample of the many possible strategies for optimising the performance of your pages and boosting your online visibility for successful natural referencing.

Don't hesitate to consult tools such as Google Lighthouse, PageSpeed Insights or SEMrush to evaluate and identify the improvements likely to have the greatest impact on your site.

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