React Scan
A browser tool that automatically highlights React components behind performance issues.
What it is
React Scan observes a running React app and automatically highlights components behind performance issues, making worthwhile updates visible on the page.
Why it is selected
It offers component-level visual cues without first adding a large amount of diagnostic code, which makes it useful for narrowing down a React performance problem.
Recommended next step
For correctness, accessibility, and maintainability issues before coding or a pull request, pair it with React Doctor. Its deterministic static analysis complements React Scan’s runtime view.
Who it suits
Frontend teams maintaining React products and tracking unnecessary updates or component-level performance bottlenecks.
Useful for
- Quickly seeing which components update often on a page under development
- Inspecting props, state, and render logic around a highlighted component
- Starting performance work from a visible problem
