When would you choose Zustand over Redux Toolkit?

Both are client state managers, but they have very different ergonomics.

Zustand advantages:

• Near-zero boilerplate — no actions, reducers, or dispatch. Create a store in ~10 lines.
• Works outside React (vanilla JS, utilities) — store is a plain JS object.
• Fine-grained subscriptions — components only re-render when the slice they subscribe to changes.
• Easy async — just write async functions in the store; no thunks or sagas needed.

const useStore = create((set) => ({
  count: 0,
  increment: () => set((s) => ({ count: s.count + 1 })),
}));

Redux Toolkit advantages:

• Opinionated structure — good for large teams where consistency matters more than brevity.
• Redux DevTools — time-travel debugging, action history, state diffs.
• RTK Query — built-in server state management (competes with React Query).
• Middleware ecosystem — logging, analytics, undo/redo.

Pick Zustand for: small-to-medium apps, new projects, when you want simplicity. Pick Redux Toolkit for: large existing Redux codebases, teams that need strict patterns and audit trails.