Many website publishers consider web performance to be purely an SEO topic. However, I can assure you that this is not the case and that it goes much further than the simple issue of visibility in Google's results pages: improved user experience, increased conversions, lower hosting costs, reduced carbon footprint... We detail all of this in this article, but that's not today's topic. We will indeed focus on the SEO gains directly attributable to a fast site: if you are here, it is because you want to understand whether it is relevant to take care of the web performance of your sites or those of your clients. To answer this question, we will start with a flashback.
A little flashback
Web performance, or " web performance ", has only been considered a discipline in its own right for about fifteen years. Previously, we made sure to have a light and fast site, but simply considering it as an extension of careful front-end development. For the older ones, those who were once called " webmasters ", this was part of the job just like natural referencing and ergonomics. We knew, even in the absence of a common framework that commanded consensus, that it was necessary to reduce the number and weight of static resources, control third-party JavaScript, or create a static version of pages in php.
Over the years and with its growing maturity, the web has seen the emergence of increasingly specific job roles, to the point of having over a hundred today, from webdesigner to SEA manager, including web copywriter and SEO consultant. One of the collateral damages of this growing specialization is web performance, which no one saw fit to champion as a discipline in its own right. This is why, for years, it was almost forgotten in the great web family. Neither UX Designers, nor SEO specialists, nor even front-end web developers wanted to hear about it.
Google and web performance
What has changed is the message Google is sending to site publishers. While in the past we only talked about keyword density and mass directory submissions for link building, Google has progressively made its ranking algorithm more complex. It has introduced new components intended to estimate the quality level of a web page, outside of any notion of authority based on backlinks. And what better way to judge the quality of content than to put numbers on the experience visitors have in real conditions? This is how the "Page Experience" project was born, materialized by the famous Core Web Vitals.
With LCP (Largest Contentful Paint), CLS (Cumulative Layout Shift), and INP (Interaction to Next Paint) metrics that it discreetly retrieves via your web browser, Google is able to judge the quality of the experience provided by your pages… But also by your entire site: this is the famous origin report found in CrUX (Chrome User Experience Report). Run a PageSpeed Insights test to access the first section called "Core Web Vitals Assessment": an "Origin" tab details what we are talking about. Google being THE essential prescriber in terms of SEO via its Search Console, web performance very quickly became a given for agencies and freelancers who have made it their profession.
Is your site as fast as your visitors expect?
Do good Core Web Vitals improve SEO?
I want to answer with the famous and essential "it depends" that we are served with in all contexts in the world of Search Engine Optimization. Because while Core Web Vitals are now officially taken into account in the mobile and desktop ranking algorithm, one should be cautious about their real impact. From the little information shared by sources within the Googleplex in Mountain View, web performance is reportedly currently only a "tie break" factor, meaning it comes into play as a last resort: if two relevant content pieces come from sources of equivalent authority and send generally the same signals, web performance can intervene to differentiate them.
If the goal is to ensure the best possible positions in the SERPs, then web performance certainly has a role to play. It's a project to consider in addition to implementing all SEO best practices. In certain hyper-competitive sectors and on certain platforms where speed is a key factor, web performance can have an even more pronounced, even essential, impact. I'm thinking in particular of Google Discover, where the correlation between page speed and visibility is evident. Try asking a news site publisher what they think of Core Web Vitals. They'll probably tell you it sometimes keeps them up at night or wakes them up at 4 AM...
A fast site to facilitate crawling
Even before the arrival of Google Page Experience and Web Vitals, a fast site ensured better crawling by bots like Googlebot and Bingbot. This is still true today: low server response times (TTFB metric) allow for optimal use of the "Crawl Budget", that time window that Google allocates to navigate your site. If your pages load faster, Google can visit more of them, which can offer 2 SEO benefits:
- more indexed pages, as the bot can discover and crawl more, possibly deeper into the site's structure;
- fresher indexed pages, as the bot can afford to visit important pages more often. We know that content freshness impacts Google's ranking algorithm.
The issue of indexability is clearly where the correlation between web performance and SEO is strongest: the link is simply mathematical.
What will be the SEO impact of web performance in the future?
If there is indeed a correlation between web performance and SEO visibility, it seems obvious that it will only increase in the future. To offer ever more relevant results to internet users and assert its technological leadership, it is in Google's interest to continue developing its Page Experience component. With the objective of representing the quality of user experience in an ever more precise and exhaustive way. It is no coincidence that it recently introduced a new INP (Interaction to Next Paint) indicator, which provides a broader view of the latencies encountered on a page following an interaction. Does your site load overly heavy and intrusive ads? No web tool or technology will allow you to bypass this problem, which will naturally be reflected in the CrUX.
So we are no longer focusing only on what happens when the page loads, but throughout its use. With CLS, which is also calculated beyond loading in 5-second intervals, Google now has 2 metrics that can be considered exhaustive given the mission entrusted to them respectively. It is highly likely that this will continue to evolve in the next 3-4 years with one certainty: when Google considers its Core Web Vitals to be representative of the real visitor experience, their weight within the ranking algorithm will significantly increase. The question will then no longer be whether there is an SEO impact, but whether you have taken the initiative!
