Google's Core Web Vitals are three technical metrics that have become both a ranking factor for SEO and a useful proxy for how your site actually feels to use. For most SME owners, the term shows up in audit reports and developer conversations without much explanation. Here's what they actually mean and why they matter commercially.
The Three Metrics
Largest Contentful Paint (LCP)
How long it takes for the largest visible element on the page to appear. Usually this is the hero image, a headline, or a featured product. Good: under 2.5 seconds. Poor: over 4 seconds.
What this measures, in practical terms: how long the customer stares at a mostly-blank page before seeing your content. If LCP is bad, customers think the page is broken or slow and many leave.
Interaction to Next Paint (INP)
How quickly the page responds when someone taps, clicks, or types. Good: under 200ms. Poor: over 500ms.
What this measures: how snappy the page feels. A site with bad INP feels laggy — buttons don't respond immediately, forms feel slow, scrolling stutters. Customers don't usually leave for this reason alone, but it dramatically affects how "premium" the site feels.
Cumulative Layout Shift (CLS)
How much the page jumps around as it loads. Good: under 0.1. Poor: over 0.25.
What this measures: how often the customer accidentally taps the wrong thing because the page moved while they were reaching for it. This is the most frustrating one — and the easiest to fix.
Why This Matters Commercially
Two reasons.
Search Engine Optimisation (SEO)
Google uses Core Web Vitals as a ranking signal. Sites that pass the thresholds rank better in mobile search, all else being equal. For local businesses, this directly affects how often you show up when someone searches "café near me" or "yoga in Tiong Bahru".
Conversion
The metrics correlate strongly with bounce rate. Sites with poor Core Web Vitals lose visitors before they reach the booking form, the menu, or the product page. Improvements typically lift conversion by 5-15%, which for a local business is the difference between a busy weekend and a quiet one.
How to Check Your Own Site
Free tools:
- PageSpeed Insights (pagespeed.web.dev) — paste your URL, get scores for mobile and desktop with specific recommendations.
- Web.dev/measure — similar, slightly cleaner interface.
- Chrome DevTools Lighthouse — for developers, but useful for spot checks.
Check on mobile specifically. Most SME sites score significantly worse on mobile than desktop, and most customers are on mobile.
The Most Common Fixes
In rough order of impact for SME sites:
- Image compression. Most sites fail LCP because of one or two huge images. Compress all images, especially hero images, and use modern formats (WebP, AVIF). This alone fixes LCP on most sites.
- Image dimensions in HTML. CLS issues are usually caused by images and ads loading in without reserved space. Setting explicit width and height attributes on images stops the layout from jumping.
- Remove unused JavaScript. INP issues are usually caused by too much JavaScript trying to run. Audit your plugins, tracking scripts, and chat widgets — most sites have 30-50% they're not using.
- Defer third-party scripts. Chat widgets, social pixels, analytics — these can usually load after the main content is visible.
- Preload critical fonts. Custom fonts often delay text rendering. Adding a preload tag in the page header fixes this.
For most SME sites, fixing Core Web Vitals is a one-week focused project, not a rebuild. The fixes are well-documented and the impact is measurable. Run the audit, find the worst metric, and start there.
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