Core Web Vitals Explained: What Google Actually Measures About Your Site
LCP, FID, CLS — they sound scary but they're simple. Here's what each one means and how they affect your Google ranking.
Google cares about user experience. Not just what your content says, but how it FEELS to use your website. That's what Core Web Vitals measure.
The three metrics
1. LCP (Largest Contentful Paint) — How fast does the main content load?
Think of it this way: you click a link, and the biggest thing on the page (usually the hero image or main text block) takes time to appear. If it appears in under 2.5 seconds, you're good.
What makes it slow: huge images, slow server, too much JavaScript loading upfront.
2. FID (First Input Delay) — How quickly can users interact?
You click a button, but nothing happens for a second because the browser is busy running JavaScript in the background. That delay is FID.
Good: under 100 milliseconds. Your site should respond to clicks/taps immediately.
What makes it slow: heavy JavaScript, third-party scripts (chat widgets, ads, trackers all competing for attention).
3. CLS (Cumulative Layout Shift) — Does stuff jump around while loading?
Ever try to click a button, but just as you're about to tap, an ad loads above it and pushes everything down? You accidentally click the wrong thing. That's layout shift, and it's infuriating.
Good: CLS score under 0.1. Elements should stay where they are.
What causes it: images without dimensions, ads loading late, web fonts changing text size.
Why this matters for your business
Since 2021, Core Web Vitals are a Google ranking factor. Two sites with similar content — the one with better vitals ranks higher. It's not a massive factor, but in competitive spaces, it matters.
How to check yours
Anested Analytics measures all three automatically when you install the tracking script. You'll see your LCP, FID, and CLS scores right in your dashboard without needing to do anything extra.
Quick fixes
- Compress images (use WebP format, set width/height attributes)
- Lazy load images below the fold
- Defer non-essential JavaScript
- Set explicit dimensions for all images and ads
- Use a CDN for faster delivery
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