// the find
open-source-labs/Reactime
Developer tool for time travel debugging and performance monitoring in React applications.
Reactime is a Chrome DevTools panel that adds time-travel debugging, a component/state graph, and render-performance tracking on top of React's Fiber tree. It's aimed at React developers who want to step through state history and spot unnecessary re-renders without instrumenting their app.
It actually gets maintained — the changelog shows real feature work (context provider/consumer visualization, variable-speed playback, dark mode) rather than a one-off bootcamp dump left to rot. It ships three separate demo apps (CRA-style, Next.js, Remix) specifically to exercise cross-framework compatibility claims instead of just asserting them. There's a real test suite covering the hard part — Fiber tree traversal and master-state reconstruction (linkFiber.test.ts, masterState.test.ts, masterTree.test.tsx) — not just UI snapshot tests.
It hard-depends on the official React Developer Tools extension being installed alongside it, since it piggybacks on that extension's global hook to reach the Fiber tree — one more moving part that can break on a Chrome or React DevTools update. Detection relies on walking unminified Fiber internals, so it silently stops finding hooks the moment a dev build gets touched by a minifying plugin (the README's troubleshooting section is basically a confession of how often this bites people). It's Chrome-only with no Firefox or Edge-specific build despite the multi-framework pitch, and there's no npm package — you can't script it or run it headless in CI, it's purely an interactive extension.