# Research notes: fast, stable small-business website on a phone

Question: What should a small business prioritize to make its website fast and stable on a phone?

All six source bodies were fetched and read 2026-09-09 (UTC).

Source register (URL / title / supported claim):

[1] https://web.dev/articles/lcp / Largest Contentful Paint (LCP) | web.dev
LCP = largest element render time; good at 2.5 s or less (75th percentile, mobile and desktop separate).

[2] https://web.dev/articles/inp / Interaction to Next Paint (INP) | web.dev
INP summarizes interaction latency; good at 200 ms or less; long main-thread work delays feedback.

[3] https://web.dev/articles/cls / Cumulative Layout Shift (CLS) | web.dev
Unexpected layout shifts; good at 0.1 or less; dimensions alone are not the only fix.

[4] https://web.dev/articles/optimize-lcp / LCP optimization | web.dev
Find the real LCP element first; avoid lazy-loading critical images; apply hints selectively.

[5] https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images / Using responsive images in HTML - MDN
srcset gives candidates, sizes gives hints; browser chooses; picture enables art direction.

[6] https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/Caching / HTTP caching - MDN
Cache-Control controls freshness; no-cache revalidates, no-store blocks; private excludes shared caches.

Priority rationale: choose the measured bottleneck, then review results.

Limitation: no real site was benchmarked.