A visitor decides in a few seconds whether to stay or leave. If the site loads slowly or "jumps" under their finger, you've lost the customer before they even see your offer. Google knows this and uses speed as a ranking signal, through Core Web Vitals.

Contents
  1. What Core Web Vitals are
  2. Why it matters for your business
  3. How to build a fast site
  4. How to measure

What Core Web Vitals are

They are three metrics that measure the real user experience:

  • LCP (Largest Contentful Paint) — how long it takes for the main element to appear. Target: under 2.5 seconds.
  • INP (Interaction to Next Paint) — how quickly the site responds to a click/tap. Target: under 200 ms.
  • CLS (Cumulative Layout Shift) — how much the content "jumps" while loading. Target: under 0.1.

Why it matters for your business

Speed isn't just a technical matter, it's a money matter:

  • Every extra second of loading lowers the conversion rate;
  • On mobile, where traffic is highest, patience is lowest;
  • Fast sites rank better and are preferred in Google's results.

How to build a fast site

Optimize images

Images are usually the main culprit. Use modern formats (WebP/AVIF), correct sizes and lazy loading for anything not immediately visible.

Reduce and defer code

Less unnecessary JavaScript, clean CSS and scripts loaded only when needed. Tracking scripts should load non-blocking and only after consent — see how we do tracking correctly.

Fonts and caching

Self-hosted fonts (no external calls) and a good caching policy reduce load time and also protect visitors' privacy.

Hosting and CDN

Performant hosting and a CDN (e.g. Cloudflare) bring content closer to the user and reduce latency. Details in the guide about hosting, cloud and performance.

In short
  • LCP < 2.5s, INP < 200ms, CLS < 0.1 — the targets to track.
  • Optimized images + less JavaScript = immediate gain.
  • Self-hosted fonts, caching, good hosting and a CDN reduce load times.
  • Measure with real data (CrUX/Search Console), not just lab tests.

How to measure

Use PageSpeed Insights and the Core Web Vitals report in Google Search Console for real data from your users, not just lab tests. Track the trend over time, not a single score.

The good news: speed can be improved. Often, a few correct optimizations make the difference between a site that "just exists" and one that actually sells. A modern frontend, built correctly, already starts with a big performance advantage.

Tags Frontend Cloud SEO