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How do you do optimistic updates in Next.js (useOptimistic, useActionState)?

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01

Understand the problem

Instant UI feedback while a Server Action runs.

nextjsuseoptimisticuseactionstateserver-actions
02

Attempt it yourself

Sketch your approach before reading the solution — that's what interviews test.

Nudge consolestandby

Stuck? Beam a request up — the console returns a conceptual nudge that guides your logic without spoiling the implementation.

03

Study the solution

useOptimistic applies a temporary optimistic state immediately while the Server Action is pending, reverting if it fails. useActionState tracks the action's result and pending status. Together they give responsive forms/mutations with proper rollback.

Solution ready — 2 min read

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04

Read the code

Optimistic like button
'use client';
import { useOptimistic } from 'react';
import { toggleLike } from './actions';

export function Like({ post }) {
  const [likes, addOptimistic] = useOptimistic(post.likes);
  return (
    <form action={async () => { addOptimistic(likes + 1); await toggleLike(post.id); }}>
      <button>♥ {likes}</button>   {/* updates instantly, reverts if action fails */}
    </form>
  );
}
05

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