The Beauty of React DOM Manipulation with Automatic Batching
React is often praised for its performance, but much of that magic comes from what happens behind the scenes. One of the most powerful improvements in modern React is automatic batching, introduced and enhanced with React 18.
🍽️ A Simple Restaurant Analogy
Imagine a group of people sitting at a restaurant table, ordering food. Have you ever seen a waiter take one order from one person, run to the kitchen, come back, then repeat this process for every single dish?
Of course not. That would be inefficient, exhausting, and a waste of time.
Instead, the waiter listens to everyone, writes down the complete order, allows changes along the way— “Sorry, cancel the lime juice. Please make it a papaya juice instead.” Once everyone is happy, the waiter goes to the kitchen once with the final order.
Fewer trips, less effort, and faster service. This is exactly the philosophy React follows.
⚛️ How React Thinks About Updates
React does not update the real DOM immediately every time state changes. Instead, it maintains an in-memory virtual representation of the DOM.
When updates are triggered—through state changes, dependency updates, or effects—React:
- Collects multiple updates
- Creates an internal update list
- Applies them together during reconciliation
This entire process is handled by React Fiber, the modern reconciliation engine.
🔁 Automatic Batching with React 18+
Before React 18, batching mainly worked inside event handlers. With React 18, batching is now automatic across many scenarios:
- Promises
- setTimeout callbacks
- Event handlers
- Async logic and effects
React waits, collects all these updates, and applies them together in a single render cycle. This process happens asynchronously, ensuring the UI remains responsive.
🚀 Why Automatic Batching Matters
Automatic batching significantly reduces the number of renders and DOM updates. Just like the waiter going to the kitchen once instead of ten times, React minimizes unnecessary work.
- Fewer renders
- Better performance
- Smoother user experience
- Scalable applications
This is why modern React applications feel faster—not because the DOM became faster, but because React became smarter.
✨ Final Thoughts
React Fiber and automatic batching are not just optimizations—they are fundamental architectural improvements. Understanding how React batches updates helps developers write more efficient code and reason better about performance.
Fewer trips to the kitchen = Faster service
Fewer renders = Better performance