React is turning 19
summary
React 19 beta introduces a build‑time React compiler (requires React 19) with a Babel plugin, an ESLint plugin and compiler transforms that strip dead code and avoid many useMemo/useCallback patterns; run the compiler healthcheck and add eslint-plugin-react-compiler to see components flagged for memoization. Server Components render noninteractive parts on the server and can query the database directly, reducing client JS. New form primitives like form actions with useActionState and useFormStatus plus async transitions remove boilerplate for pending and state. createRoot replaces render and the release is experimental, not production ready.
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chapters (10)
- 0:00Introduction and welcome
- 1:15React 19 features overview
- 3:22React compiler explained
- 6:55Server components deep dive
- 12:07Form actions and hooks
- 17:05New use API and improvements
- 18:29Ref and context API updates
- 20:35Document metadata handling
- 21:16Migration to React 19
- 22:18Production readiness and next steps
