Redux — Predictable Global State Management for JS Apps

What Redux Does

• Single source of truth — one global state tree
• State is read-only — updated via dispatched actions
• Pure reducers — (state, action) => newState
• DevTools — time-travel debugging
• Middleware — thunks, sagas, listeners for side-effects
• RTK Query — server state with caching (alternative to React Query)
• createSlice — auto-generate actions + reducers
• Immer — write mutating code, RTK converts to immutable

Architecture

Dispatched action → reducer(s) → new state → subscribers rerender. Store holds state, useSelector subscribes, useDispatch sends actions. Middleware intercepts actions for async work.

Self-Hosting

Client library only.

Key Features

• Redux DevTools browser extension
• Time-travel debugging
• RTK Query (server state)
• createSlice / createAsyncThunk
• Listener middleware
• TypeScript-first
• React, Vue, Angular, Svelte bindings
• SSR-compatible

Comparison

FAQ

Q: Is Redux obsolete? A: No. Code written with RTK is about as concise as Zustand, but you keep DevTools time travel and maintainability at scale.

Q: RTK Query vs React Query？ A: Features overlap. RTK Query fits into the Redux ecosystem and shares the store; React Query is lighter with a cleaner API.

Q: When should I use Redux vs Zustand? A: Very large apps, strict architecture, cross-team collaboration → Redux. Small-to-medium apps that prize simplicity → Zustand.

Sources & Credits

• Docs: https://redux.js.org
• RTK: https://redux-toolkit.js.org
• GitHub: https://github.com/reduxjs/redux
• License: MIT