PageSpeed

PageSpeed is a common term for how fast a web page loads, and at the same time the name of a popular Google tool — PageSpeed Insights — that analyzes a site's performance and suggests what to improve. Speed today matters both for the visitor and for a page's position in search results.

How PageSpeed Insights works

The tool combines two kinds of data. The first is lab measurements powered by the Lighthouse engine, which test a page in a controlled environment. The second is field data (the CrUX report) gathered from real Chrome users. From this, PageSpeed Insights produces a score from 0 to 100 and reports Core Web Vitals such as LCP, CLS and INP.

Beyond the score, the tool returns a list of concrete recommendations: eliminating render-blocking resources, compressing images, cutting unused JavaScript and CSS, and improving server response time as measured by TTFB.

Practical application

Webmasters and SEO specialists use PageSpeed to diagnose performance bottlenecks and prioritize optimization work. Typical steps include enabling caching and compression (gzip or Brotli), applying lazy loading for images, using a CDN, and adopting modern image formats like WebP and AVIF.

A significant part of the score depends on infrastructure — fast hosting with a low server response time directly improves TTFB and LCP, so code optimization is best paired with a performant environment. It's worth remembering that PageSpeed is a starting point, not a goal in itself: what matters is the real load time a user perceives, not just the number in the report.