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performanceWeb Platform

LCP Hero Optimization

MUST

MUST: LCP images (hero, banner): Use `loading="eager"` + `fetchpriority="high"` + `decoding="async"`. Add `<link rel="preload" as="image">` in head. NEVER lazy-load above-the-fold content.

Preload above-the-fold images and prioritize LCP elements for fast perceived loading

Bad

Good

Why it matters

Largest Contentful Paint (LCP) is a Core Web Vital measuring when the largest content becomes visible. Hero images are often the LCP element. Preloading and eager loading ensures they render as fast as possible.

References

Built by Gleb Stroganov, design engineer at Evil Martians.

The rules come from other people's skills and guidelines — Vercel, Rauno Freiberg, @Ibelick, impeccable, Emil Kowalski, Tailwind, RAMS — each one credited on the Sources page. The work here is extraction and wiring: every rule is pulled into one corpus, given a good and a bad example you can operate, a MUST/SHOULD/NEVER rule an agent can paste, and a link back to where it came from.