Slow site, lost customer: a Core Web Vitals guide
If your site takes more than 3 seconds to load, you lose half your visitors. Here's what Core Web Vitals are and how to improve them.
Speed is no longer a technical luxury: it's business. More than half of users abandon a site that takes over three seconds to load, and Google knows it. That's why it measures experience with Core Web Vitals and uses them for ranking.
What Core Web Vitals are
They're three metrics that sum up the real user experience: LCP (how long the main content takes to appear), INP (how quickly the site responds to your clicks) and CLS (whether elements jump around while loading). Google evaluates them on mobile.
Why they affect you
A fast site converts more and ranks better. Every tenth of a second counts: it improves experience, reduces bounce and boosts your chances of ranking high.
How to improve them
- Modern image formats (WebP/AVIF) at the right size
- Reserved space for images and ads (no more jumps)
- Less unnecessary JavaScript and deferred loading of heavy assets
- Good hosting and well-configured caching
How to measure your site right now (free)
Go to Google's PageSpeed Insights, enter your URL and check the mobile tab: there are your Core Web Vitals with real user data. A mobile score under 50 is urgent; between 50 and 89, clear room for improvement; 90 or above, you're in the good zone (where the sites we build score).
Slow WordPress: the pattern we see most
Most slow sites we audit share a recipe: an overloaded multi-purpose theme, fifteen plugins, unoptimised images and cheap hosting. Sometimes optimisation is enough; often it pays more to rebuild on a modern, lightweight foundation. The numbers after the switch speak for themselves.
What changes when your site flies
Speed isn't an engineers' metric: it's money. Industry studies agree that every extra second of loading cuts conversions by around 7%, and that 53% of mobile visits abandon a page that takes more than three seconds. It works in reverse too: when we rebuild a slow site on a modern foundation, the effect shows in bounce rate, pages per visit and — within weeks — Google positions. It's one reason we build all our web design projects with static generation and images served at the exact size of each screen.
We rebuild slow sites with modern technology that scores above 90 on Lighthouse. Want to know how yours does? We'll do a no-obligation review.
Frequently asked questions
What PageSpeed score is 'good enough'?
On mobile: 90+ is excellent, 50-89 has room for improvement and under 50 is costing you customers. Focus especially on real user data (CrUX) if your site has traffic.
Optimise my WordPress or rebuild the site?
If the problem is a heavy image or one plugin, optimise. If the foundation is a multi-purpose theme with fifteen plugins, optimisation hits a ceiling fast: rebuilding on a modern base usually pays off over 2-3 years.
Does speed really affect SEO?
Yes, doubly: it's a direct ranking signal (Core Web Vitals) and an indirect one via behaviour — a slow site spikes bounces, which Google reads as unhelpful content.
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