A slow website loses visitors and drops on Google. The good news: a few simple levers are enough to win most of the battle. Here is what you need to understand and do.

Why speed matters

• For visitors: beyond 2–3 seconds, many give up. On mobile, it is even more pronounced.
• For Google: speed is one of the ranking criteria (via the Core Web Vitals). A fast site ranks better.

The Core Web Vitals (Google’s 3 metrics)

Google sums up the loading experience with three indicators:

Indicator	Measures	Target
LCP	Time to display the main content	< 2.5 s
INP	Responsiveness to interactions (click, scroll)	< 200 ms
CLS	Visual stability (elements that jump)	< 0.1

In short: the page must load fast, react fast, and not jump while loading.

The concrete levers (in order of impact)

1. Compress and size your images — the number-one cause of slowness. A 4 MB photo should drop below 300 KB, at the right size, in a modern format (WebP/AVIF).
2. Good hosting — a slow server drags everything down (see hosting). A static site is unbeatable on speed.
3. Caching — avoid recalculating every page (crucial for a dynamic site).
4. Fewer scripts — every plugin, tracker or widget slows things down. Keep only what is strictly necessary.
5. Reserve space for images and ads to avoid jumps (good CLS).
6. Fonts — load them cleanly, without blocking the text from displaying.

How to measure

Free tools provide a diagnosis and suggestions:

• PageSpeed Insights (Google) — score + Core Web Vitals + recommendations.
• The browser’s built-in tools (the “Performance”/“Lighthouse” tab).

Measure before and after each change: you optimise what you measure.

Key takeaways

Performance is not a technical detail: it is money (visitors retained) and SEO. Start with images and hosting — they are 80% of the result for 20% of the effort. And remember: the fastest site is the one that loads the fewest useless things.