Free website performance tools

Interactive tools for interpreting Core Web Vitals, planning optimization work and estimating savings. They run in your browser and store nothing on our servers unless a tool says so.

Core Web Vitals checker: interpret your LCP, INP and CLS Classify values you have already measured, with the source and units kept clear. Open tool

Website performance checklist: plan and track your fixes Work through performance checks with evidence, and keep your progress in this browser. Open tool

Image savings calculator: compare bytes before and after optimization Estimate the byte savings from image variants you have already created or measured. Open tool

Core Web Vitals thresholds: LCP, INP and CLS reference Read the metric boundaries alongside the measurement conditions that make them meaningful. Open tool

PageSpeed Insights analyzer: interpret public-page performance Request a public-page report and distinguish a fresh lab test from historical real-user data. Open tool