⏱️ Performance — Speed

Image compression reduces file size without a noticeable loss in visual quality, and it’s usually the single biggest performance win available on a typical business website, since unoptimized photos are often the heaviest files a page loads. Modern formats like WebP and AVIF compress far more efficiently than older formats like JPEG or PNG while looking just as good. Lazy loading delays loading images or content that are further down the page until the user actually scrolls near them, rather than loading everything at once the moment the page opens.

Caching stores a copy of a page or resource so it can be served instantly on repeat visits. Caching happens at multiple levels — in the visitor’s own browser, at a hosting provider’s servers, and often through a Content Delivery Network (CDN) that stores cached copies of a site in data centers around the world, so a visitor in Cape Town and a visitor in London can both load a page quickly from a server near them.

Core Web Vitals are Google’s official, measurable performance metrics. LCP (Largest Contentful Paint) is how long it takes for the largest visible piece of content to fully render — the "good" threshold sits at under 2.0 seconds. INP (Interaction to Next Paint) is how quickly the page responds after a user interacts with it — a "good" INP is under 200 milliseconds. CLS (Cumulative Layout Shift) is how visually stable a page is while loading — a "good" score is under 0.1. A page generally "passes" Core Web Vitals when at least 75% of real visits meet the "good" threshold across all three simultaneously.