Google's three measures
They are measured on real visitors and assessed at the 75th percentile: at least three visitors out of four must have a «good» experience.
- LCP (Largest Contentful Paint): how long the main content of the page takes to appear. Good: within 2.5 seconds.
- INP (Interaction to Next Paint): how ready the page is to respond to a tap or click. Good: within 200 milliseconds. It replaced the old FID in 2024.
- CLS (Cumulative Layout Shift): how much the page «jumps» while loading, moving text and buttons. Good: within 0.1.
Where to measure them
- PageSpeed Insights: shows real-visitor data (when there is enough) and a lab test.
- Google Search Console: the Core Web Vitals report groups the site's pages by result.
- Browser tools (Lighthouse, the Performance tab) to track down the cause of a problem.
How much they weigh on rankings
They are one of the experience signals Google uses, but they do not replace content: a useful but slightly slow page can still rank, and a lightning-fast empty page will not.
Where they weigh most is on people: those who wait too long leave, and those who see a button move as they tap it get annoyed. That is why they are worth looking after anyway.
The fixes that matter most
- Images: modern formats (WebP, AVIF), sizes suited to the screen, deferred loading for those below the first screen. The main image, however, should not be deferred.
- Fonts: few families and weights, with text visible immediately while the font loads.
- Third-party scripts (analytics, chat, widgets, ads): each one slows things down. Keep those you need and load them after the content.
- Server and cache: compression, browser cache, modern protocols and, if needed, a content delivery network (CDN).
- Page stability: reserve space for images, banners and ads before they load; the cookie banner must not push the content around.
Lab data and real data
The lab test simulates an average phone on an average network and is good for finding causes; real data shows what visitors actually experience and is what Google considers. Real data is an average of roughly the last 28 days, so improvements show up gradually.
A four-step plan
- 1. Measure the pages that bring the most visits or enquiries, not just the home page.
- 2. Find the main cause (often heavy images or too many scripts).
- 3. Fix one thing at a time and measure again.
- 4. Check now and then: a new script or a new image can make everything worse.
What you find in our packages
The technical audit in the SEO packages covers speed, mobile and indexing. Websites start from €1,350: see the website packages and, for what to do in the first months after launch, SEO for a new website: the first 90 days.