Site Speed and Core Web Vitals: SEO and Sales

A fast website matters both to users and to Google. When a page loads slowly, some visitors leave without waiting, and the search engine takes user experience into account in its rankings. In this article we explain the Core Web Vitals metrics, how to check them and practical ways to speed up your site.

What are Core Web Vitals?

Core Web Vitals are the three key metrics Google uses to measure user experience:

• LCP (Largest Contentful Paint) — the time it takes for the largest element on the page (usually the main image or heading) to appear. Good result: under 2.5 seconds.
• INP (Interaction to Next Paint) — how quickly the page responds to clicks and taps. Good result: under 200 milliseconds.
• CLS (Cumulative Layout Shift) — unexpected movement of elements while the page loads. Good result: below 0.1.

How does speed affect SEO?

Google treats page experience as one of its ranking signals and evaluates sites mainly by their mobile version. Speed alone does not replace good content, but it can make the difference between pages of similar quality. More importantly, on a fast site users view more pages and get in touch more often.

How can you check your site?

• PageSpeed Insights — shows both real-user data and the results of a lab test.
• Google Search Console — the "Core Web Vitals" report groups the problematic pages of your site.
• Lighthouse — runs a performance, accessibility and SEO audit in the browser's developer tools.

Lab tests help you find problems, while real-user data reflects the result Google actually sees.

8 practical ways to speed up your site

1. Optimise images. Use WebP or AVIF and serve an appropriately sized image for each screen (srcset).
2. Defer off-screen images. Images further down should load only when the user reaches them, while the main image loads with priority.
3. Load fonts properly. Preload the key fonts so text does not jump when the font swaps.
4. Reduce third-party scripts. Analytics, chat widgets and ad code should load after the page opens or when the user needs them.
5. Give elements dimensions. When the width and height of images and banners are set in advance, content does not shift while the page loads.
6. Use caching and a CDN. Serve static files from a server close to the user, with long-term caching.
7. Cut down JavaScript and CSS. Remove unused code and serve compressed files.
8. Improve server response time. Slow database queries and weak hosting reduce the effect of every other optimisation.

A real example: nss.az

We applied these steps to our own website: we replaced images with WebP versions sized to the screen, started analytics and chat scripts after the page loaded, and eliminated layout shifts by preloading fonts. As a result, in the Lighthouse mobile test the performance score of the home page rose from 84 to 97, and that of the service pages from 79 to 98.

Let's check your site's speed together

As part of our SEO service, we run a technical audit of your site, improve its Core Web Vitals and plan the work needed for visibility in search engines. You can also read our article on common SEO mistakes. Write to us for a free consultation.