In the world of modern web development, two JavaScript frameworks dominate the landscape: Angular and React. While Angular is a full-fledged framework developed by Google, React is a library maintained by Facebook. The question of performance often comes up in debates among developers. In this article, we’ll compare these two technologies and explain why React often stands out in terms of performance.

Architecture and Philosophy

Angular: A Complete Framework
Angular is a full MVC (Model-View-Controller) framework that enforces a rigid structure on your application. It includes many built-in features, such as:

• A complex templating system
• Dependency injection
• Routing tools
• Form management

This "all-in-one" approach can be beneficial for large enterprises but often adds unnecessary overhead.

React: A Flexible Library

React, on the other hand, focuses on one thing: building efficient user interfaces. This minimalist philosophy allows for:

• Greater flexibility in technology choices
• A gentler learning curve
• Easier integration into existing projects

Performance: Why React Excels

1. Virtual DOM vs. Change Detection
   React uses a Virtual DOM, which minimizes costly manipulations of the real DOM. When a component’s state changes, React:
2. Creates a new virtual representation of the DOM
3. Compares it with the previous version (diffing algorithm)
4. Updates only the parts that have changed

Angular uses a change detection system that regularly checks all bindings for changes. This approach can become costly in complex applications.

2. Rendering Optimization
   React provides fine-grained control over the rendering process thanks to:

• shouldComponentUpdate to avoid unnecessary re-renders
• React.memo for component memoization
• Hooks like useMemo and useCallback

Angular also offers optimizations (such as OnPush), but they are often more complex to implement.

3. Bundle Size
   React applications generally have:

• Faster initial load times
• Smaller JavaScript bundles
• Less "boilerplate" code

Angular, with its module system and many built-in features, often produces larger bundles.

4. Better Real-Time Performance
   For applications requiring frequent UI updates (dashboards, collaborative tools), React’s Virtual DOM approach shows measurable advantages:

• Faster response times
• Less "jank" (occasional freezes)
• Better user experience on less powerful devices

When to Choose Angular?

React isn’t always the best solution. Angular may be preferable for:

• Teams that appreciate an enforced structure
• Large enterprise projects requiring consistency
• Applications that heavily rely on Angular’s built-in features

If performance is your primary criterion, React generally delivers better results thanks to its efficient Virtual DOM, granularity, and minimalist philosophy. However, the choice between Angular and React should also consider other factors, such as ecosystem, team expertise, and project-specific needs.

For developers looking to maximize performance while maintaining flexibility, React remains the most compelling solution in 2023. Its growing popularity and vibrant ecosystem only strengthen this position.