Redux vs MobX

Definition

A comparison between Redux's strict, immutable, functional architecture and MobX's mutable, observable-based reactive architecture.

Explain Like I'm New

Redux is strict math: state is completely frozen, and you dispatch actions to generate new copies. MobX is magic: state is fully mutable. You literally just write `state.user.name = 'John'`, and MobX automatically 'observes' the change and magically updates any React component looking at that data.

Real World Example

A team of object-oriented Java developers often prefers MobX because it relies heavily on Classes and mutability. A team of functional programming enthusiasts prefers Redux.

Common Use Cases

•Architectural paradigms

Interactive Example

// 🟢 MOBX ARCHITECTURE (Object-Oriented, Mutable, Observable)
import { makeAutoObservable } from "mobx"

class TimerStore {
  secondsPassed = 0 // Mutable state!

  constructor() {
    makeAutoObservable(this) // Makes React watch this object magically
  }

  increaseTimer() {
    this.secondsPassed += 1 // Direct mutation! Completely legal in MobX.
  }
}

export const timerStore = new TimerStore()

Interview Questions

basic

Which library relies on strict Immutable Updates: Redux or MobX?

intermediate

Why is debugging sometimes considered harder in MobX than in Redux?

Flash Cards

Question

Which relies on Immutable?

Click to reveal answer

Answer

Redux. (MobX explicitly relies on Mutable data).

Question

Why debugging harder?

Click to reveal answer

Answer

Because MobX data can be mutated from ANYWHERE at ANY TIME. There is no strict 'Action -> Dispatch -> Reducer' trail. Redux DevTools provides a flawless, time-stamped history of exactly WHY the state changed, which is invaluable.