Perf Recorder

Records memory, CPU, DOM, network & UX metrics (INP/CLS/LCP) for any web app without opening DevTools.

Perf Recorder measures how a web app performs across a whole session — without opening DevTools (which would distort memory readings). It captures: • Memory — JS heap usage • CPU — per-tab renderer CPU usage • DOM — element, node and event-listener counts (leak signals) • UX metrics — INP, CLS, LCP, FCP, Long Animation Frames, FPS, long tasks • Network — HTTP requests/responses and WebSocket frames • Console output and uncaught errors Data streams to disk as you record, so the tool's own buffers don't inflate the memory it measures, and a reload or crash won't lose your run. On Stop you get a structured JSON report plus a clean CSV time-series — stored only on your machine; nothing is ever uploaded. Use it to hunt memory leaks, find CPU/jank hotspots, and catch UI-responsiveness regressions. Works on any web app.