Core Web Vitals for WordPress: a practical fix-it guide

The three metrics that matter

LCP (Largest Contentful Paint) — how long until the biggest above-the-fold element renders. Target under 2.5s.

INP (Interaction to Next Paint) — how quickly the page responds to interaction. Target under 200ms. Replaced FID in 2024.

CLS (Cumulative Layout Shift) — how much the layout shifts as it loads. Target under 0.1. Caused mostly by images without dimensions and ads loading late.

Fixing LCP on WordPress

The biggest LCP element on most WordPress sites is the hero image. Serve it in WebP/AVIF, declare width and height, and use fetchpriority='high'. Most modern caching plugins do this automatically.

Slow TTFB poisons LCP — fix the host or fix the cache before chasing front-end tweaks.

Fixing INP and CLS

INP is usually killed by heavy JavaScript — Elementor, third-party trackers, and chat widgets are common culprits. Defer non-critical JS and audit your tracking stack.

CLS fixes are mechanical: add width/height to every image, reserve space for ads and embeds, and avoid injecting content above existing content after the page loads.