Cases
Performance & CROPerformance & CRO

STS Benelux

A chimney-services site rebuilt for speed and conversion: LCP cut by four seconds, perfect accessibility, and 20+ CRO wins that turn visitors into leads.

STS Benelux

The board state

Functional, but leaking speed and leads

STS Benelux had a working Next.js site that quietly underperformed. Mobile scored 69, LCP dragged at 7.1 seconds, and the pages lacked social proof, urgency, and CTAs that actually asked for the business. We ran a full technical and conversion audit and built a multi-phase plan.

The move

Speed first, then persuasion

Across three sessions we rebuilt the Core Web Vitals: LCP fell from 7.1s to 3.1s, total blocking time from 280ms to 23ms, and time-to-interactive from 7.8s to 3.1s. We converted hero images to WebP, fixed oversized dimensions, replaced JavaScript-heavy components with CSS, and lazy-loaded everything below the fold. Accessibility, best practices, and SEO all hit 100.

Then we optimised for conversion against 10 CRO benchmarks: more than 20 improvements including action-oriented CTAs per service, a 4.9/5, 600+ customer social-proof bar under the hero, value-led form titles, response-time guarantees at the point of action, and urgency copy grounded in marketing psychology.

The result

Faster and more persuasive, everywhere

The combination delivered a site that loads in a fraction of the time and asks for the sale on every page, turning STS Benelux’s traffic into qualified leads instead of bounces.

-4.0s

LCP (7.1s to 3.1s)

-257ms

total blocking time

100

accessibility, SEO, best practices

20+

CRO quick wins

Built with

Next.jsWebPnext/dynamicCore Web Vitalsmarketing psychology