Core Web Vitals are three metrics Google uses to measure real-world experience: how quickly your page shows up, how fast it responds when tapped, and whether things jump around while loading. Slow or janky sites get pushed down — and, more importantly, they lose visitors before those visitors ever become leads.
LCP — Largest Contentful Paint (loading)
What it measures: how long until the main content (usually your big hero image or headline) appears.
Good score: under 2.5 seconds.
What hurts it: huge unoptimized images, slow hosting, bloated themes, too many scripts. This is the metric most small-business sites fail.
INP — Interaction to Next Paint (responsiveness)
What it measures: how quickly the page reacts when someone taps a button or link.
Good score: under 200 milliseconds.
What hurts it: heavy JavaScript and too many third-party tools (chat widgets, trackers, pop-ups) all fighting for the browser's attention.
CLS — Cumulative Layout Shift (visual stability)
What it measures: how much the page jumps around as it loads. Ever gone to tap a button and an ad shoved it down? That's layout shift.
Good score: under 0.1.
What hurts it: images and ads without reserved space, fonts that swap and reflow text.
Why this matters for your business
Beyond rankings, speed is money. Faster sites keep more visitors, get more form fills and calls, and convert better — this is one of the seven issues behind a site that gets traffic but no leads. A one-second delay can measurably cut conversions, especially on mobile.
How to check your scores (free)
Run your homepage through Google's PageSpeed Insights (pagespeed.web.dev). It gives you the three scores plus specific recommendations. Test on mobile — that's how most local customers visit.
The cheapest improvements
- Compress and properly size images (often the single biggest win)
- Serve modern image formats like WebP
- Remove unused plugins, scripts, and third-party widgets
- Use quality hosting — cheap shared hosting is slow
- Reserve space for images and embeds to stop layout shift
You don't always need to rebuild. Many sites can be meaningfully sped up with targeted fixes — which is exactly what my speed optimization service does.