Page speed refers to how quickly a web page loads its content for a user or automated client. Key metrics include Time to First Byte (TTFB), First Contentful Paint (FCP), Time to Interactive (TTI), and Largest Contentful Paint (LCP) — all part of Google's Core Web Vitals framework.
For web scraping applications, page speed matters because JavaScript-heavy pages that take longer to render require more compute time per request. Understanding performance characteristics helps you choose the right rendering tier — lightweight HTTP requests for fast static pages, full browser rendering for slow JS-heavy sites.
Google's PageSpeed Insights, Lighthouse, and WebPageTest are the primary tools for measuring page performance. AlterLab's API can extract performance metrics and page weight data to build automated performance monitoring pipelines.