How to Check and Improve Your Website Speed

Website speed is both a ranking factor and a conversion factor. Google has used page speed as a ranking signal since 2010. In 2021, this expanded to Core Web Vitals - a set of standardised experience metrics measuring load speed (LCP), interactivity (INP) and visual stability (CLS). Slow pages lose both rankings and customers.

Measure your current speed

Use Google PageSpeed Insights (pagespeed.web.dev) to measure LCP, INP and CLS for both mobile and desktop. This is lab data - useful for identifying issues. For field data (real user experience), check the Core Web Vitals report in Google Search Console. Field data is what Google uses for ranking decisions. A page scoring "Good" on all three metrics is unlikely to lose rankings on speed grounds.

The highest-impact improvements

Improve hosting: shared hosting causes high Time to First Byte (TTFB), which directly impacts LCP. Managed WordPress hosting (Kinsta, WP Engine, SiteGround) reduces TTFB to under 300ms. Optimise images: convert to WebP format (25-35% smaller than JPEG), add lazy loading to all below-fold images, and preload the LCP image. Implement caching: WP Rocket or LiteSpeed Cache eliminates PHP processing for repeated page loads. Remove render-blocking scripts: use WP Rocket's defer JavaScript feature to prevent scripts from blocking page render.

WordPress-specific speed optimisation

Install WP Rocket (paid, ~$59/year): handles caching, image lazy loading, JavaScript deferral and database optimisation in one plugin. Install ShortPixel or Imagify: automatically compresses and converts images to WebP on upload. Add Cloudflare (free): provides CDN delivery, which speeds up page loading for visitors far from your server. Remove unused plugins: every installed plugin - even inactive - can add CSS and JavaScript to your pages.