Why can React Hook Form (RHF) perform better than traditional Formik forms?

Short answer

React Hook Form uses the Uncontrolled pattern and registers inputs with Refs, avoiding a full form render on every keystroke, unlike Formik's Controlled State approach.

Explanation

Formik updates central state for every character typed, re-rendering every field and slowing large screens. RHF registers fields and listens for changes locally, re-rendering only the field related to an error and using very little memory.

Code example

import { useForm } from 'react-hook-form';

function LoginForm() {
  const { register, handleSubmit, formState: { errors } } = useForm<{ email: string }>();

  const onSubmit = (data: { email: string }) => console.log(data);

  return (
    <form onSubmit={handleSubmit(onSubmit)}>
      <input {...register("email", { required: "Email is required" })} />
      {errors.email && <span>{errors.email.message}</span>}
      <button type="submit">Sign in</button>
    </form>
  );
}

Common mistakes

• Calling watch() at the top of a component without selecting specific fields, re-rendering the entire component and losing RHF's main benefit.

Follow-up questions

• How do Controlled Components and Uncontrolled Components differ, and when should you prefer each?
• How do you manage Dynamic Field Arrays whose number of fields changes in a form?

Sources

• React Hook Form docs — Get Started