How do you handle forms state in React?

Form state management options in React: Uncontrolled forms: use native HTML form behavior with ref for values. Minimal re-renders. Good for simple forms. Controlled forms: React state mirrors every input. Flexible but causes re-render on every keystroke. React Hook Form: the most popular form library. Uses uncontrolled inputs under the hood for performance — minimal re-renders. const { register, handleSubmit, formState: { errors } } = useForm(); <input {...register("email", { required: true, pattern: /\S+@\S+\.\S+/ })} />. Integrates with Zod/Yup for schema validation. Formik: older but still widely used controlled-form library with field arrays, async validation. TanStack Form: new, framework-agnostic form library from the creators of TanStack Query. When to use Redux for forms: almost never — form state is local UI state that doesn't need to be global. Use form libraries or local useState. Only put the form's submitted data in global state if other parts of the app need it.