How page speed impacts user retention

A beautiful site that takes five seconds to become usable on 4G is a sales leak. People do not wait; they bounce to the next result. Core Web Vitals are simply a standardised way of measuring how annoying you are to use.

Performance is decided in design: image weight, font loading, third-party scripts, and whether you need a 40-plugin WordPress stack for a five-page brochure.

We default to fast stacks (Astro, Next.js, disciplined Shopify) and treat performance budgets as part of the fixed scope — not a post-launch “optimisation phase.”

Written for operators by twenty9 agency — agentic-first web, SEO, and automation for UK SMBs.