Core Web Vitals: why they matter for Google and for your sales

Open your site on your phone, on a mobile connection, the way any customer would. If it's slow to load, if the text jumps around while the page settles, if you tap a button and it doesn't respond right away, that customer leaves before even reading what you offer. Core Web Vitals measure exactly these sensations, and Google uses them to decide how to rank you. Let's look at what they are, why they matter for ranking and for sales, and how to improve them in concrete terms.

What Core Web Vitals are

Core Web Vitals are three metrics Google uses to try to quantify the real experience of someone visiting a page. Each measures a different aspect.

• Loading speed: how much time passes before the main element of the page (usually the large image at the top or the block of text) is actually visible. It's the metric people perceive as "the site is slow".
• Responsiveness: how quickly the page responds when you tap a button, open a menu or fill in a field. A site that appears right away but freezes for a moment on every tap is just as frustrating.
• Visual stability: how much the page moves on its own while it loads. The classic example is the button that shifts an instant before your tap because an image has just appeared above it, and you end up clicking the wrong thing.

Google collects this data from real users browsing with Chrome, not just from lab tests. That means field performance counts, on your visitors' real devices and connections.

Why Google uses them (and what it changes for you)

Google has a direct interest in sending people to pages that open well: if the first-page results were all slow, people would use a different search engine. That's why Core Web Vitals are among the signals that feed into ranking.

It's fair to keep expectations in check: the quality of the content and its relevance to the search weigh more. A lightning-fast site with poor content won't climb the rankings. But, with content being equal, speed becomes the tiebreaker, and it's the one you can act on with targeted technical work. In practice: improving the Vitals rarely jumps you from page five to page one, but it often wins you back the positions you were losing to a lighter competitor.

Sales are the real scorecard

Let's leave Google aside for a moment. The strongest reason to look after Core Web Vitals is money. Every extra second of waiting is people closing the tab: it happens especially on mobile, where patience is minimal and the connection is shaky. On an eCommerce site the effect shows up all along the funnel, from the product page that's slow to appear to the checkout that stalls at the worst possible moment, when the customer already has their card in hand.

In the projects we handle, speed isn't a technical box to tick at the end of the job: it's a design choice that starts from the first line. It's far cheaper to build a lightweight site from the outset than to chase performance afterwards, when every fix risks breaking another.

How to improve them, in practice

Most performance problems come from a few recurring causes. Here's where to act first:

• Images: they're almost always the biggest weight. Use modern formats, size the files for the space they'll be shown in (don't load a huge image only to shrink it with CSS) and always specify width and height, so the browser reserves the space and the page doesn't jump.
• Fonts and third-party scripts: every widget, chat, tracker or advertising pixel adds code that slows things down. Keep only the ones you actually use and load them so they don't block the content from appearing.
• Hosting and cache: a slow server undoes every optimization. A good caching configuration and, where needed, a CDN shorten the times for visitors coming from far away.
• Layout stability: reserve the space for images, banners and ads before they load, so nothing shifts at the last instant.
• Lean code: a custom-built site loads only what it needs. Templates full of features you don't use drag dead weight onto every page.

A practical tip: always measure before and after, both in the lab and on real user data, and focus the work on the pages that bring traffic and conversions. Optimizing a page nobody visits is wasted time.

An example: when the site is also a business card

Performance matters even when you don't sell directly online. For photographer Vincenzo Ingrassia, who specializes in luxury weddings and is published in Vogue Italia, the site is an editorial portfolio made of high-quality images: exactly the kind of content that, handled badly, would sink loading times. When we rebuilt it in 2025 we had to hold together two opposing needs, images that do the work justice and pages that open quickly. It's a balance you design, not one you improvise at the end of the job.

Let's talk about your site

If you suspect your site is slow but don't know where to start, we can help. With our websites and eCommerce service we build pages designed to be fast and stable from the foundations, and we fix Core Web Vitals where there are already problems. Book a free call: we'll look at your site's metrics together and tell you where you're leaving visitors and sales behind.