The gold standard for web performance testing and optimization
Build websites that your users love.
Understanding site health through Core Web Vitals (CWV)
Your site’s discoverability is determined by many SEO factors — including Core Web Vitals. Improve your site usability and SEO using WebPageTest’s free Core Web Vitals test.
LCP
A low LCP score means your users experience snappy page speeds throughout your site. This score is measured in milliseconds.
INP
A low INP score means your webpage is responsive to user interactions and provides a smooth user experience.
CLS
A low CLS score means your user’s experience is stable and accessible when navigating across layouts, buttons, links, and content.
Trusted by the world's top brands
Why web performance experts choose WebPageTest
In-depth metrics + Waterfalls
Slice data by location, browser version, and device type to compare Core Web Vitals scores or performance indicators. Identify specific impact areas on the waterfall to quickly diagnose performance issues.
Correlated Insights
Combine WebPageTest metrics with real user insights from RUM for a holistic view of website performance and user experience.
Powerful visualizations
Easily share videos, .gifs, and filmstrips with your team and benefit from out-of-the-box dashboards and AI-powered smartboards to seamlessly collaborate and resolve issues on a unified platform.
Developer-first API & integrations
Scale and 'programmatically run WebPageTest with our easy-to-use API and integrate into your dev workflows with our easy-to-use API with the NPM wrapper for Node JS, Github Actions, VC Code Extension, Slackbot, Grafana and more.
