Free Page Speed Insights Simulator Online — No Signup Required

A page speed simulator measures and visualizes how a web page loads under different network conditions — 3G mobile, 4G LTE, and broadband — without needing to run tests from an actual slow connection. Google's Core Web Vitals (Largest Contentful Paint, First Input Delay, Cumulative Layout Shift) are ranking signals, and most users on mobile networks experience slower load times than developers testing on office broadband. Simulating slow connections surfaces performance issues that are invisible during local development.

The simulator captures a waterfall diagram showing each resource load time, connection time, and time to first byte. Render-blocking resources (CSS and JavaScript in the document head that must load before rendering starts) are highlighted because they directly delay the point at which users see page content. The tool provides actionable suggestions: resources to defer, candidates for compression, and third-party scripts that are adding significant latency.