Key takeaways
- LCP, INP, and CLS are Google ranking signals. Hit the targets.
- Slow sites lose users and rankings. Fix both together.
- Common wins: image optimisation, less JS, fixed dimensions, CDN.
Google uses Core Web Vitals as ranking signals. Slow, janky sites rank worse. Fast, smooth sites rank better. It's measurable and fixable.
The three metrics
Largest Contentful Paint (LCP): how fast the main content appears. Aim for under 2.5 seconds. First Input Delay (FID), now Interaction to Next Paint (INP): how quickly the page responds to clicks. Aim for under 100ms. Cumulative Layout Shift (CLS): how much the page jumps around while loading. Aim for under 0.1.
Why they matter
Users bounce from slow sites. They get frustrated when buttons don't respond or content jumps. Google rewards sites that give a good experience because that's what users want.
Common fixes
- Optimise images: compress, use modern formats (WebP), lazy load
- Reduce JavaScript: defer non-critical scripts, minimise render-blocking
- Fix layout shift: set dimensions on images and embeds
- Use a CDN and caching for static assets
FAQs
Google Search Console, PageSpeed Insights, or Chrome DevTools. All report these metrics.
Often yes. Image optimisation, caching, and script deferral can make a big difference.
Start with LCP (Largest Contentful Paint). Slow main content is the most common complaint. Fix images and render-blocking resources first.