Do you actually need a global state library, or is the problem smaller than that?

Most state is either server data or props you can lift. A global store is the last tool you reach for.

Server data is not your state

Most "state" in a React app is either data your server owns (let a fetching library handle it) or values a parent could pass down as props. Only real shared client state, like a user preference or a sidebar toggle three unrelated components care about, belongs in a store.

Think of the state I want to share: does it come from the server, and could I pass it as a prop or lift it to a common parent instead of reaching for a global store?

When you do need a store

Zustand fits most cases with almost no setup, Jotai suits fine-grained reactivity on individual atoms, and Redux Toolkit fits teams that need an audit trail and structured conventions.

I have [describe your state]. Would Zustand, Jotai, or Redux Toolkit be overkill here, and how do they compare on setup complexity and bundle size for a small-team Next.js App Router project?