business-solutions
Lighthouse 95+ as a floor, not a goal
How and why we treat web performance as a non-negotiable engineering constraint.
Published 2026-05-12 · 4 min read
When we ship a website, mobile Lighthouse Performance ≥ 95 is the floor — the minimum acceptable. Most agencies treat it as a stretch goal. Here is why we don’t.
What it actually means
A Lighthouse Performance ≥ 95 on mobile (slow 4G) means:
- LCP ≤ 1.8 s
- Total Blocking Time ≤ 150 ms
- CLS ≤ 0.05
- Total transfer ≤ 250 KB gzipped
These are achievable on first build if you choose your stack with this constraint in mind. They are nearly impossible to retrofit later.
The decisions that make it free
- SSG, not SSR or CSR. Astro, Hugo, Eleventy — the HTML is pre-rendered and cached at the edge.
- Zero JS by default. Only the islands that need interactivity ship JS.
- Tailwind with purge. CSS gzipped under 14 KB per route.
- AVIF / WebP images. With explicit width + density variants.
- Subset web fonts. Latin + Arabic only. Preload the one used in the LCP.
- Cloudflare in front. Brotli + HTTP/3 + 1-year cache on /_assets.
That’s the whole list. There is no clever trick. The trick is that we said no to React-by-default.