Page speed is one of the few technical SEO factors that directly affects every visitor, every pageview, and every conversion. It's also one of the easiest areas to get wrong — a single oversized hero image, a blocking third-party script, or a slow database query can tank Core Web Vitals scores and push a site down the rankings. These guides cover the metrics that matter most (LCP, INP, CLS, TTFB), how to diagnose which one is hurting you, and the specific fixes that give the biggest speed gains for the least engineering effort. Written by developers who care about real-world performance, not synthetic benchmark scores.