Core Web Vitals sound like something for developers. In practice they describe what every visitor feels: how fast the page appears, whether it responds when tapped and whether it jumps around while loading. That makes them a marketing metric too.
The three numbers, in plain language
- Largest Contentful Paint (LCP) measures how long it takes for the main content, usually the hero image or headline, to appear. Google treats 2.5 seconds or less as good.
- Interaction to Next Paint (INP) measures how quickly the page reacts when someone taps or clicks. Under 200 milliseconds feels instant.
- Cumulative Layout Shift (CLS) measures how much the page moves while loading. A score under 0.1 means buttons stay where people expect them.
These are measured on real visitors' devices, not just in a lab, which is why a page can feel fast in the office and slow on a customer's phone.
Why marketing teams should care
Every paid click, social post and email campaign ends on a page. If that page is slow or unstable, some of the people you paid to bring there will leave before they read a word. Speed is part of the user experience Google considers in search, and it shapes how far your ad spend actually goes.
A slow landing page is a tax on every campaign that points to it.
Where the problems usually come from
When we audit marketing sites, the same causes appear again and again:
- Oversized hero images and videos. A full-screen video or an uncompressed photo is often the single largest cause of a slow LCP.
- Too many tracking scripts. Analytics, pixels, chat widgets and heatmaps each add a little delay. Together they can make a page feel sluggish when tapped.
- Late-loading banners and fonts. Cookie bars, promo strips and web fonts that arrive after the content push everything down the page.
- Heavy page builders. Visual builders make editing easy but often ship far more code than a page needs.
A field guide for your next campaign
Before launch
- Test the landing page on a mid-range phone over mobile data, not on office Wi-Fi.
- Compress the hero image and serve it in a modern format such as WebP.
- Reserve space for images, embeds and banners so nothing jumps when they load.
- Review every tracking tag and remove the ones nobody uses.
After launch
- Check the Core Web Vitals report in Google Search Console every month.
- Compare conversion rates on fast and slow pages; the difference often makes the business case for you.
- Treat any drop in the scores like a broken link: something changed, and it is worth finding out what.
Make it a shared number
The most effective teams we work with put Core Web Vitals on the same dashboard as traffic and conversions. When marketing can see that a new widget slowed the page, and developers can see what a faster page did for sign-ups, speed stops being a technical chore and becomes something everyone owns.
You do not need a perfect score. You need pages that load quickly, respond instantly and stay still while people read them. Your visitors notice the difference, even if they never know the metric's name.