Web Page Analyzer

WebPageTest provides a highly detailed breakdown of page loading, including Core Web Vitals metrics like First Contentful Paint (FCP), Largest Contentful Paint (LCP), and Cumulative Layout Shift (CLS). It also generates a visual filmstrip view that shows exactly what your website looks like at every fraction of a second as it loads. This allows developers to pinpoint exactly when rendering bottlenecks occur.

Yes, WebPageTest allows you to select specific, real-world mobile devices like the Motorola Moto G or Apple iPhone to run your performance tests. It also lets you throttle the connection speed to simulate slower 3G or 4G networks. This is crucial for understanding how a site performs for users on lower-end hardware or poor cellular connections.

While Google Lighthouse runs a simulated test locally in your browser, WebPageTest uses actual physical devices in various global locations to provide real-world data. WebPageTest offers a much more granular, technical breakdown of DNS lookup, TCP connections, and SSL negotiation. Lighthouse is better for quick audits, whereas WebPageTest is the industry standard for deep diagnostic analysis.

Yes, WebPageTest offers a robust free tier that allows users to run public performance tests from dozens of global locations. The free version provides access to waterfalls, connection views, and content breakdowns without requiring an account. For heavy API usage or private instances, they offer paid enterprise plans.