React Doctor
Use React Doctor to scan a React codebase for security, performance, correctness, and architecture issues. Use the diagnostics to prioritize fixes and improve overall code health.
Usage
npx -y react-doctor@latest . --verboseUse @latest intentionally to run the newest rule set.
Workflow
- Run the command at the project root and capture the full output.
- Verify diagnostics before patching: confirm each reported issue against actual runtime behavior, project conventions, and framework constraints.
- Fix validated issues, starting with highest severity diagnostics.
- Re-run React Doctor and confirm the diagnostics list is reduced.
- Re-run project checks (lint, tests, typecheck/build as applicable) to ensure no regressions.
Rule Coverage (47+)
React Doctor includes 47+ rules. The categories below are representative examples, not an authoritative or exhaustive rule list.
- Security: hardcoded secrets in client bundle, eval()
- State & Effects: derived state in useEffect, missing cleanup, useState from props, cascading setState
- Architecture: components inside components, giant components, inline render functions
- Performance: layout property animations, transition-all, large blur values
- Correctness: array index as key, conditional rendering bugs
- Next.js (in projects using Next.js): missing metadata, client-side fetching for server data, async client components
- Bundle Size: barrel imports, full lodash, moment.js, missing code splitting
- Server Actions (in projects using Next.js): missing auth in server actions, blocking without after()
- Accessibility: missing prefers-reduced-motion
- Dead Code: unused files, exports, types
Score
- 75+: Great
- 50-74: Needs work
- 0-49: Critical