A fast website loads its main content within 2.5 seconds, responds straight away when a visitor clicks and does not jump around while it loads. That is exactly what Google’s three Core Web Vitals measure: LCP, INP and CLS. Speed affects how many visitors stay and buy, and it is one of the signals Google takes into account, but it never replaces relevant content. The usual culprits behind a slow site are heavy images and too many third-party scripts, and both can be fixed.
Why speed matters for your business
Visitors do not wait. A page that lags or stutters loses people before they have read what you offer.
In the Milliseconds make millions study, commissioned by Google and carried out by Deloitte and 55, researchers followed 37 European and American brand sites and more than 30 million sessions. A 0.1 second improvement in mobile site speed raised conversion rates by 8.4 percent for retail sites and 10.1 percent for travel sites.
What about Google? Google’s own page experience documentation says it always seeks to show the most relevant content, even when the page experience is poor, and that good Core Web Vitals results do not guarantee top rankings. A great page experience can, however, contribute when many pages answer the same question equally well. The biggest payoff is usually with your visitors, not in your ranking.
The three Core Web Vitals and their thresholds
Google measures the experience with three metrics. According to web.dev, a page counts as good when:
- LCP (Largest Contentful Paint) is 2.5 seconds or less. It measures how quickly the largest visible element, often a big image or heading, appears.
- INP (Interaction to Next Paint) is 200 milliseconds or less. It measures how quickly the page reacts when a visitor clicks, taps or types. INP replaced the older FID metric on 12 March 2024, so any guide that still talks about FID is out of date.
- CLS (Cumulative Layout Shift) is 0.1 or less. It measures how much the content moves around while the page loads, for example when a banner suddenly pushes down the text you were reading.
The values are measured at the 75th percentile. That means at least three out of four visits should meet the threshold, split by mobile and desktop. The page has to be fast for a customer on an older phone, not just on your office computer.
How to measure your own website
Two free Google tools go a long way.
PageSpeed Insights
Paste your address into PageSpeed Insights. You get two kinds of results, and the difference matters:
- Field data comes from real Chrome users over the previous 28 days, via the Chrome User Experience Report. According to Google’s own description, no field data is shown if the page has too few real-user samples, which is common for smaller businesses.
- Lab data is a simulated test run under controlled conditions. It is good for finding what slows you down, but it may not capture what real visitors experience.
The 0 to 100 score comes from the lab test. Focus on the field data and the three metrics instead.
Search Console
If your site is verified in Google Search Console, you will find the Core Web Vitals report. It uses the same real-user data and groups pages with a similar experience, such as all your product pages. Each group is rated Good, Needs improvement or Poor, and the worst of the three metrics decides the rating.
Why is my website slow? Common causes and fixes
Most slow websites share the same handful of problems:
| Cause | What happens | Fix |
|---|---|---|
| Heavy images | Large, uncompressed images make the main content load slowly and hurt LCP. | Compress, use modern formats such as WebP or AVIF and serve the right size for each screen. |
| Too many third-party scripts and trackers | Analytics tools, ad pixels, chat widgets and cookie banners make their own requests and keep the browser busy, hurting INP and LCP. | Remove what you do not use, load the rest later and choose lighter alternatives. |
| Page builders and bloated themes | General-purpose themes and drag-and-drop tools load lots of code the page never uses. | Build with a lighter theme or a static site that only ships what is needed. |
| Cheap shared hosting | The server responds slowly, and everything else waits for that first response. | Move to better hosting or serve prebuilt pages from a CDN. |
| Web fonts | Several fonts in many weights delay the text and can make the layout jump when the font swaps in. | Use fewer fonts and weights, host them yourself and reserve space. |
| No caching or CDN | Every visit builds the page from scratch and fetches it from a distant server. | Turn on caching and put the site behind a CDN close to your visitors. |
web.dev calls them a common cause of slowdowns, partly because they sit outside your control: they fire more network requests to more servers and keep the browser busy. If your own code is lean and the site is still sluggish, look there first.
As web.dev notes on LCP, nothing can happen in the browser until the server delivers the first byte, so a faster server response improves every other metric.
Privacy and speed go together
Every tracker on your site, from cookie-based analytics to ad pixels and retargeting, is one more script to download and run. Those same scripts are often why you need a cookie banner, which is yet another script.
Fewer trackers therefore means both better privacy and a faster site. You can still understand how visitors use your website with cookieless analytics that collects no personal data and needs no consent.
Speed is not a one-off fix either. New images and tools creep in over time, so it needs regular follow-up as part of continuous optimisation.
Frequently asked questions
Do Core Web Vitals affect my Google ranking?
Yes, but less than many think. Relevant content comes first, and good scores guarantee nothing, but a good page experience can help when several pages are equally relevant.
Why does PageSpeed Insights show no field data for my site?
Field data needs enough visits from real Chrome users over the past 28 days. If your site has little traffic you only get lab data, which is still useful for finding what slows you down.
What is a good PageSpeed score?
Focus on the three metrics rather than the score: LCP of 2.5 seconds or less, INP of 200 milliseconds or less and CLS of 0.1 or less, for at least 75 percent of visits.
What is the most common problem on slow websites?
Usually heavy images and too many third-party scripts. Both are fairly easy to fix.
How Almano helps
We build websites static-first and without third-party tracking scripts. Visitor analytics runs without cookies and without personal data, so there is no cookie banner weighing the page down. After launch we measure and improve every month, so the site stays fast as the content grows. Read more on our services page.
If you want to know why your site feels slow and what would make the biggest difference, book a free call or run your domain through our free audit on the homepage.
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