Total page weight is within the mobile budget (≤ 1.6MB)

Total page weight directly governs how long a marketing page takes to load on the mobile devices that now account for the majority of web traffic. ISO-25010 resource-utilisation defines bandwidth consumption as a key quality attribute. Google's research pegs 1.6MB as the point at which bounce rates on mobile 4G connections begin to climb non-linearly — above that threshold each additional 100KB correlates with a measurable user drop-off. Marketing pages built with AI coding tools frequently blow past this budget by combining an unoptimised hero image with multiple third-party analytics SDKs and an unpurged CSS framework, each of which individually seems harmless but collectively produce a 3–5MB page that loads in 8–12s on a 4G connection.

Work through each asset category with a size target — the hero image is almost always the highest leverage starting point.

Run next build and check .next/analyze/ (with @next/bundle-analyzer) for JS chunk sizes. For the hero, convert to WebP and drop quality to 80:

npx sharp-cli --input public/hero.jpg --output public/hero.webp --format webp --quality 80

For ongoing enforcement, add a Lighthouse CI budget assertion in .lighthouserc.json under "total-byte-weight" so page weight regressions block the deploy.