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Performance

The real cost of a slow website (in dollars, per month)

12 January 20266 min read

A 4-second mobile load is invisible to you and devastating to your conversion rate. Here’s how to put a dollar figure on it — and why fixing it is usually a one-day job.

If your homepage loads in four seconds on 4G, and a competitor loads in one, you’re losing somewhere between 20% and 40% of your potential leads. The cost is silent — most owners never see the bounce, because the visitor never arrived.

The math

Take a small service business with 1,000 organic visitors a month and a 3% baseline conversion rate. That’s 30 enquiries. Speed studies (Google, SOASTA, Cloudflare) consistently show conversion drops 7% per additional second of load time on mobile.

Move from 4 seconds to 1 second and you recover roughly 21% of your conversion: 30 enquiries become 36. If your average closed enquiry is worth $400, that’s $2,400/month — about $29,000 a year — for one technical fix.

Why most sites are slow

  • Hero images uploaded at 4MB instead of 200KB.
  • Render-blocking JavaScript in the head.
  • Hosted on a generic shared server in the wrong country.
  • Web font sprawl (six families, one used).
  • Animation libraries imported globally, used on one button.

How fast is fast enough

The honest target is sub-1.5s LCP on a 4G phone. Lighthouse 90+ is a leading indicator, not the goal. The goal is that the visitor stops noticing they’re waiting.

What we do by default

  • Cloudflare Pages hosting — global edge, no shared-server lottery.
  • Image optimisation as a build step (AVIF + WebP fallbacks, responsive sizes).
  • One web font family, two weights max, swap not block.
  • Server-side render where it counts; client-side only where interactivity demands it.
  • JS bundle budget: under 100KB compressed for the first paint.

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