A slow website quietly costs you customers. The good news is that performance is measurable, and most improvements come from a handful of well-understood techniques.
The three metrics to watch
- Largest Contentful Paint (LCP): how quickly the main content appears. Aim for under 2.5 seconds.
- Interaction to Next Paint (INP): how responsive the page feels when people click or type.
- Cumulative Layout Shift (CLS): how stable the layout is while loading.
Quick wins
Serve modern image formats at the right size, reserve space for images and embeds, and load fonts efficiently. These changes alone often fix most layout shift and loading issues.
Ship less JavaScript
Render on the server where possible, split heavy components into separate bundles and only load them when they are needed. A 3D scene or a chart library should never delay your headline from appearing.
Measure with real-user data, not only lab tests — your customers use slower devices than your developers.
Treat performance as a budget that every new feature must respect, and your site will stay fast as it grows.
Tags
- #Next.js
- #Performance
