How does Effector differ from Redux?

ReactJunior~2 min read

Effector and Redux are both state managers, but they are built on completely different philosophies. In short:

Effector is a reactive, declarative system; Redux is an imperative, reducer-based architecture.

Let's break it down point by point, with examples.

1. Approach to state management

	Effector	Redux / RTK
Paradigm	Reactive	Imperative
How the logic is described	"What depends on what" (dataflow)	"What to do when an event happens" (reducers)
Updates	Automatic, based on dependencies	Manual, through `dispatch()`
Philosophy	Describe the data flow	Describe how the reducer changes the store

Effector:

javascript

const increment = createEvent()
const $count = createStore(0).on(increment, c => c + 1)

Redux:

javascript

const increment = () => ({ type: 'increment' })
const reducer = (state = 0, action) =>
  action.type === 'increment' ? state + 1 : state

2. Architecture and principles

	Effector	Redux
State	Several independent `store`s	One large `store` (or slices)
Side effects	Through `createEffect()` (built in)	Through `thunk`, `saga`, `observable`, etc.
Subscriptions	Reactive (`.watch`, `.map`, `sample`)	Through `useSelector()` / middleware
Typing	Excellent TypeScript integration	Better with Redux Toolkit, but still bulky
Performance	Minimal re-renders, fine-grained reactivity	Can trigger unnecessary re-renders
SSR	Out of the box	Requires manual state management

3. Working with asynchrony

Effector manages asynchronous effects built in:

javascript

const fetchUserFx = createEffect(async id => {
  const res = await fetch(`/api/users/${id}`)
  return res.json()
})

fetchUserFx.done.watch(({ result }) => console.log('User', result))

In Redux you need to write middleware by hand:

javascript

const fetchUser = id => async dispatch => {
  dispatch({ type: 'pending' })
  const res = await fetch(`/api/users/${id}`)
  dispatch({ type: 'success', payload: await res.json() })
}

Effector does this declaratively, without middleware.

4. Flexibility and scaling

Effector lets you describe dependencies explicitly:

javascript

sample({
  source: $user,
  clock: updateClicked,
  fn: (user) => ({ ...user, updated: true }),
  target: $user,
})

In Redux, such a reactive link is not possible - you need to manually dispatch a chain of actions.

Effector does not require a global store: you can create a local store for any component or module. Redux, on the other hand, assumes a single centralized structure (store -> reducer tree).

5. Performance and subscriptions

Effector subscribes a component only to the data it needs. When other stores change, the component does not re-render.

Redux, even with useSelector, often triggers unnecessary re-renders unless you use memoization (shallowEqual, reselect, etc.).

6. Code and DX (Developer Experience)

Effector:

javascript

const addTodo = createEvent<string>()
const $todos = createStore<string[]>([]).on(addTodo, (list, todo) => [...list, todo])

Redux Toolkit:

javascript

const todosSlice = createSlice({
  name: 'todos',
  initialState: [],
  reducers: {
    addTodo: (state, action) => { state.push(action.payload) }
  }
})

Effector means less boilerplate, more declarativeness and reactive links. Redux Toolkit is more imperative, but familiar to developers from older ecosystems.

7. When to choose which

Scenario	What to choose
Small app	Zustand, Jotai, Effector
Large SPA with business logic	Effector
Enterprise / legacy / a team already familiar with it	Redux Toolkit
Strict dataflow and reactivity needed	Effector
A clear "step by step" flow needed	Redux Toolkit

8. In one sentence

Effector is a reactive dataflow manager: you describe the links, and everything updates itself. Redux is an imperative action-reducer manager: you dispatch actions, and everything updates manually.

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