You've already left a website because it took too long to load. So have I. Everyone does it, and nobody announces it: we close the tab and go elsewhere. That's the real cost of a slow site. Not a red score in an audit tool — visitors leaving before they've even seen what you offer.
Speed is not an engineering topic. It's a trust topic. A site that responds instantly signals a business in control of its craft. A site that lags, jumps around while loading, or takes a second to react to a click signals the exact opposite. And that judgment forms before a single line of text is read.
What Core Web Vitals measure
Google formalized this user experience with three metrics, the Core Web Vitals. They matter for search rankings, but their real value lies elsewhere: they measure what a visitor feels.
LCP (Largest Contentful Paint): the time before the main element of the page is displayed. It's the moment the visitor thinks "there it is, I can see the content." Target: under 2.5 seconds.
CLS (Cumulative Layout Shift): visual stability. It's what happens when the page moves during loading and you click the wrong button because an image appeared above it. Target: a score under 0.1 — in other words, a page that barely moves.
INP (Interaction to Next Paint): responsiveness. The delay between your click and the page's visible reaction. Target: under 200 milliseconds. Beyond that, the interface feels sluggish.
Three metrics, three sensations: "I see it fast," "nothing jumps," "it responds." A visitor knows none of these acronyms, but perceives all three constantly.
Why this translates into conversions
A contact request, a quote, a purchase: every conversion is a chain of small decisions to stay. Every second of waiting, every layout jump, every unanswered click is an opportunity to leave. On mobile, with an average connection and ten open tabs, tolerance is even shorter.
There's also an indirect effect: Google uses these metrics as a ranking signal. A slow site starts with a double handicap — ranked lower, so fewer visitors, and visitors who convert less well once they arrive. The reverse is virtuous: a fast site attracts more traffic and converts it better.
What I concretely do
On the sites I build, performance is not an optimization added at the end. It's a consequence of the initial choices.
Static whenever possible. A pre-generated page waits for no database and no server-side execution: the file is ready, it gets served. That's the case for this site — and it's the main reason it loads fast, even on shared hosting.
No third-party scripts. Every tracker, chat widget, or font loaded from an external CDN adds requests, delay, and layout shifts. This site ships no third-party scripts and self-hosts its fonts — I detailed the process in the article on self-hosted web fonts, published right here.
Sized and compressed images. An oversized image is the most common cause of a bad LCP, and an image without declared dimensions the most common cause of a bad CLS. Modern formats, explicit width and height, lazy loading for anything below the fold.
Measure before and after. PageSpeed Insights and the Core Web Vitals report in Search Console show real visitor data, not a lab test. That's where you verify the choices hold up over time.
None of this is spectacular. It's discipline: don't add what slows things down, measure, fix.
Where to start
If you want to know where your site stands, run a test on PageSpeed Insights: it's free and the verdict comes in thirty seconds. Then three questions are enough: does the main content appear in under 2.5 seconds? Does the page move while loading? Do interactions respond immediately?
If the answer to any of these bothers you, the problem is rarely mysterious — and it can be fixed. Often, a few targeted interventions are enough to move a site into a different league.
Want an opinion on your site's performance, or a site designed to be fast from day one? Let's talk.