Google measures website speed with three indicators, the Core Web Vitals, and takes them into account in its ranking, even though the relevance of the content matters more. Above all, visitors on a phone do not wait.
Measure in two minutes
Open PageSpeed Insights, paste your website address and run the analysis. Look mainly at the “Mobile” result. The thresholds Google sets for a good result:
- Main content display (LCP): under 2.5 seconds.
- Response to a click (INP): under 0.2 seconds.
- Visual stability (CLS): under 0.1. In other words, nothing should jump while loading, like a button that moves just as you click.
The most common causes
- Photos that are too heavy. A phone photo often weighs 3 to 5 MB.
- Plugins and scripts piling up. Every carousel, chat window or tracking tool adds code to load.
- No caching. The browser downloads the logo and styling again on every page.
- Overloaded hosting. The server takes more than a second to respond, before even sending the page.
- Too many fonts. Each variant (bold, italic…) is one more file.
Example: a 4 MB homepage photo, resized to the width of a screen and converted to WebP, often ends up under 200 KB with no visible difference. On an average mobile connection, that saves several seconds.
Where to start
- Resize and convert images: this is often the biggest gain.
- Disable what is no longer used: plugins, widgets, old tracking tools.
- Enable compression and caching with your hosting provider.
- Measure again to check the gain.
We carry out this check-up: measurement, a list of fixes ranked by impact, then implementation if you wish. Contact us.
Source: Google Search Central, “Core Web Vitals” · Accessed 26 September 2026.