Core Web Vitals, Explained Without the Jargon
Google grades every page on three measurements, and they affect where you rank. Here's what LCP, INP and CLS actually mean in plain English.
Somewhere in a report from your developer or an SEO tool, you've probably seen three acronyms flagged in red: LCP, INP, CLS. Together they're called Core Web Vitals, and Google uses them as a ranking signal.
They sound technical. What they measure isn't — each one corresponds to something a visitor physically experiences.
LCP — how long until the page looks ready
Largest Contentful Paint measures how long it takes for the biggest visible thing on screen — usually your hero image or headline — to finish loading. It's the moment a visitor stops staring at a blank area and starts reading.
Google wants this under 2.5 seconds. Over 4 seconds is graded poor.
What usually causes a bad LCP
- Enormous, uncompressed hero images — a 4 MB photo where a 200 KB WebP would look identical.
- Slow or overloaded hosting, which is the single most common culprit on cheap shared plans.
- Render-blocking scripts and fonts loading before anything is drawn.
- Theme and plugin bloat on template-based sites.
INP — how quickly the page reacts when you touch it
Interaction to Next Paint measures the lag between a visitor tapping something and the page visibly responding. You know the feeling: you tap a menu, nothing happens, you tap again, and now it's opened twice.
Target is under 200 milliseconds. It's almost always caused by too much JavaScript competing for the browser's attention — often tracking scripts, chat widgets, and pop-up tools that were each added "just this one thing" over the years.
CLS — how much the page jumps around while loading
Cumulative Layout Shift measures unexpected movement. You go to click a button, an image finishes loading above it, everything shifts down, and you click an ad instead. Infuriating, and entirely preventable.
Target is under 0.1. The fix is usually straightforward: reserve space for images and ads before they load, and stop injecting banners above existing content.
How much do they really affect rankings?
Less than relevance and content quality — Google has been clear that a fast page with poor content won't outrank a slow page with the right answer. But between two comparable pages, speed is a genuine tiebreaker.
The larger argument for fixing them isn't rankings at all: it's that every one of these measurements corresponds to a visitor getting annoyed. Faster pages convert better whether or not Google ever notices.
Where to start
- 1Run your homepage and one key landing page through Google's PageSpeed Insights and read the field data, not just the lab score.
- 2Compress and convert your largest images to WebP. This alone often fixes LCP.
- 3Audit third-party scripts and remove anything nobody actually uses.
- 4Set explicit dimensions on images and embeds to eliminate layout shift.
- 5If your hosting is the bottleneck, no amount of front-end work will save you — move.
If your scores are red and you'd rather not untangle it yourself, we can audit the site and tell you exactly which fixes will move the numbers most.
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