WhoRenderedThis от Avinash

How it works:
Simply hover over any element on a React-powered website, and an overlay instantly shows you the component name, file path, and line number where that element was created. Click to pin the overlay and explore the full component hierarchy — see parent components all the way up the tree, complete with their source locations.

Key features:
- Instant component identification — No more guessing which component rendered what
- Source location mapping — Jump directly to the source file and line number
- Parent chain exploration — Understand the component hierarchy at a glance
- Version-aware detection — Works with React 16, 17, 18, and 19+
- Lightweight & non-intrusive — Only activates when you need it

Perfect for:
- Debugging unfamiliar React codebases
- Understanding component boundaries in large applications
- Learning how other React apps are structured
- Quickly navigating to the right source file
Built for developers, by developers. Open source on GitHub.