Google's Core Web Vitals — LCP, INP and CLS — directly influence rankings and conversion rates. Amazon famously calculated that every 100 ms of latency cost 1% in sales. After optimising dozens of sites, here are the 12 techniques ranked by real-world impact.

1-3. Caching layers (biggest wins)

1. Server-level page caching

A cached HTML response served by LiteSpeed Cache, NGINX fastcgi_cache or a CDN costs under 10 ms; WordPress rendering from scratch costs 300–800 ms. This is always the single largest win. On shared hosting, use LiteSpeed Cache; on VPS, configure NGINX caching or Redis object cache.

2. Browser caching + compression

Set long expires headers for static assets and enable Brotli compression. A single .htaccess or NGINX snippet handles both:

gzip on; gzip_types text/css application/javascript image/svg+xml;

3. Database object caching

Redis or Memcached cuts repeated query cost on dynamic pages like WooCommerce carts and search results.

4-6. Images and media

4. Convert to WebP/AVIF

Converting a 900 KB JPEG hero image to AVIF typically yields 120–180 KB with no visible loss. WordPress 6.x supports both natively; otherwise use a converter plugin or CDN.

5. Explicit dimensions on every image

Width/height attributes prevent layout shift (CLS). This one-line fix is the most common CLS killer.

6. Lazy-load below the fold — but never the hero

Lazy-load images, iframes and video below the fold. Explicitly exclude your LCP image (fetchpriority="high" instead).

7-9. Render-blocking resources

7. Critical CSS + deferred JS

Inline the CSS needed for above-the-fold content and defer everything else. Plugins like LiteSpeed Cache or Autoptimize generate this automatically.

8. Font-display: swap + font subsetting

Custom fonts cause invisible text (FOIT) and CLS. Use swap, subset to Latin characters, and preload only the 1–2 weights you actually use.

9. Remove unused plugins and scripts

Audit with Query Monitor. Every plugin adds PHP execution and often front-end scripts. Removing five "nice-to-have" plugins is routinely worth 300+ ms.

10-12. Server and network

10. Choose the right server location

Physics matters: 70 ms of unavoidable latency exists between New York and Frankfurt. Host where your audience is — see our hosting benchmarks for US and EU TTFB data.

11. Use HTTP/3 (QUIC)

Most modern hosts support it; it reduces connection overhead on mobile networks noticeably.

12. Add a CDN for global audiences

Cloudflare's free tier covers most sites. If your audience spans the US and Europe, a CDN is non-negotiable for consistent LCP.

Typical results

Applying techniques 1, 4, 5, 7 and 12 to a standard WordPress site on mid-tier hosting consistently takes LCP from ~3.2 s to under 1.5 s in our tests. Start there, measure with PageSpeed Insights, and iterate.