PerfLens

Real-session performance observer. Reads page timing locally and sends nothing anywhere.

PerfLens watches the pages you actually browse and tells you how they perform — no synthetic run, no lab throttling, no account. - Reads real user timing from the live session: Core Web Vitals, long tasks, layout shifts, and resource weight. - A DevTools panel for the detail and a popup for the score at a glance. - Explains every finding in plain language, and shows exactly how the score was computed. - Detects the framework and build setup of the page so the advice fits the stack.