Web App for Firefox Performance Analysis
"Capture a performance profile. Analyze it. Share it. Make the web faster.
The Firefox Profiler visualizes performance data recorded from web browsers. It is a tool designed to consume performance profiles from the Gecko Profiler but can visualize data from any profiler able to output in JSON. The interface is a web application built using React and Redux and runs entirely client-side.
Mozilla develops this tool to help make Firefox silky smooth and fast for millions of its users, and to help make sites and apps faster across the web."