Understanding React Native Fabric and How to Implement It in Your Project

Features of React Native Fabric

The fabric architecture brings several new features that collectively improve performance, consistency, and developer experience in React Native development. Below are some of the most notable features:

1. Synchronous Rendering

Fabric uses the JavaScript Interface (JSI) to enable direct, synchronous communication between JavaScript and native code. JSI allows JavaScript to call native functions directly in memory, bypassing serialization. This enables real-time UI updates, as changes in JavaScript are immediately reflected in the native UI.

Synchronous rendering reduces latency, making animations, scrolling, and user interactions smoother and more responsive. Furthermore, it delivers a near-native performance which is critical for complex apps.

2. C++ Core

Fabric's rendering logic is implemented in a shared C++ core, a cross-platform codebase that handles UI rendering for all supported platforms. The C++ core processes rendering tasks efficiently due to its high performance. It minimizes platform-specific code by providing a unified rendering engine.

3. Immutable Shadow Tree

Fabric architecture uses an immutable shadow tree to represent the UI hierarchy (the structure of components like <view> or <text>). This tree is read-only, ensuring no unintended changes occur during rendering.

When JavaScript updates the UI, Fabric creates a new shadow tree for the updated state, reusing unchanged nodes from the previous tree. This immutable approach prevents conflicts when multiple threads request UI changes simultaneously.

4. Yoga Layout Engine

Fabric continues using the popular Yoga layout engine, which powers layout calculations in React Native. Yoga supports a Flexbox-style layout system and ensures consistent rendering of components, no matter the screen size or platform.

Under Fabric, Yoga has tighter integration with the rendering pipeline, resulting in faster and more accurate layout updates. It also works seamlessly with the new immutable shadow tree.

5. Concurrent React Support

Fabric architecture brings full support for Concurrent React. It means that the React Native app can now handle multiple UI updates at the same time. In older versions, updates had to finish one at a time, which could lead to slow or frozen interfaces.

With Concurrent support, Fabric can determine which UI update should be prioritized and which update should wait. With Fabric, UI updates can be started, paused, or resumed in the background without blocking the user experience.

6. Improved Native Interoperability

In the old React Native architecture, the bridge that connected JS and native code was often slow. This made it tricky to build custom features or work with native components efficiently.

Fabric in React Native allows an easy communication between JavaScript and native modules. Developers can now build features that feel more "native" without running into performance issues or complex workarounds.

How Fabric Changes the React Native Architecture

_{Image courtsey: React Native}

To fully appreciate the impact of React Native Fabric, it's important to understand how it changes the underlying structure of the framework. React Native's original setup, legacy architecture, had three separate threads: the JavaScript thread, the shadow tree layout thread, and the UI thread. These threads communicated through an asynchronous bridge, which often caused delays and performance issues in complex apps.

With the introduction of the Fabric architecture, this system was completely redesigned. The new architecture eliminates the slow bridge and introduces a more direct, synchronous communication path between JavaScript and native components. It also unifies the rendering logic across platforms with a shared C++ core and introduces modern concepts.

Key Benefits of Fabric

Fabric in React Native has brought some amazing benefits to the developer community and solved many of the long-standing pain points in mobile app development.

1. Type Safety

React Native Fabric brings stronger type safety to the table, which is a big win for reliability. It maintains component property synchronisation between JavaScript and native code through code generation. This means that rather than waiting for a failure to occur at runtime, you will catch it at build time if something doesn't match, like a prop being passed in with the incorrect type.

In larger apps where multiple teams may be working on the same components, this type of safety net is extremely helpful. Developers can rely on the system to identify errors early rather than speculating or manually verifying integration points. It helps maintain cleaner, more consistent code and cuts down on debugging time.

2. Shared C++ Core

With Fabric, React Native introduces a shared rendering engine built in C++, used across platforms like iOS, Android, and Windows. This shared core standardizes how UI is handled on different platforms, making the behavior more consistent no matter where your app runs.

Beyond consistency, it simplifies maintenance. If the team at Meta makes a fix or enhancement to the rendering logic, it applies everywhere. It also opens the door for React Native to expand more easily into new platforms in the future without starting from scratch.

3. Host Platform Interoperability

One of Fabric's most practical advantages is how smoothly it integrates with native platforms. It enables layout calculations to happen synchronously, which native systems expect. That means you can embed React Native views into native apps or use native components inside React Native screens without layout glitches or delays.

Additionally, it works well with native frameworks and third-party libraries, particularly those that handle gestures or animations or need instant feedback. All things considered, Fabric helps React Native feel more like a natural extension of the native environment rather than an isolated system.

4. Improved Performance

New React Native architecture was developed with improving performance in mind. Fabric supports concurrent React features. Which means React Native can decide which elements to render first, and important task takes priority while others run in the background. Additionally, by flattening views, Fabric simplifies view hierarchy, allowing apps to render more quickly and with less overhead.

Lazy component loading is another helpful enhancement. Fabric reduces startup time and memory usage by loading native views only when necessary rather than all at once. When taken as a whole, these improvements contribute to a more seamless and responsive user experience.

5. Reduced Serialization Overhead

JavaScript and native code had to communicate using serialised JSON messages in the previous React Native architecture, which wasn't exactly lightweight. Fabric adopts JavaScript Interfaces (JSI), which is a more effective technique that enables direct communication between the two sides.

This effective communication can speed up interactions and decrease lag by reducing the amount of time spent converting data back and forth. When working with heavy updates like scrolling or animations, every millisecond is important. Thanks to fabric, your app can become more responsive, free of needless performance snags.

Use Cases of React Native Fabric

In this section, we'll highlight where the Fabric architecture really shines in real-world app development.

1. Large-Scale Applications

For apps with dozens of screens, complex UI logic, and multiple teams working together, maintaining consistency and preventing bugs is a major challenge. React Native Fabric offers strong type safety and shared rendering logic across platforms, which makes it easier to scale your app without scaling the complexity.

2. Apps with Embedded Native Views

If you are integrating React Native into an existing native app, Fabric makes the process far smoother. Its improved interoperability means React Native views can sit comfortably alongside native ones without layout glitches or delays.

3. Performance-Critical Products

Apps that rely heavily on smooth animations, fast response times, or real-time updates benefit a lot from the performance boosts Fabric brings. With concurrent rendering and reduced overhead between JS and native code, it helps you squeeze more speed and responsiveness from the same hardware.

4. Cross-Platform App

Thanks to the shared C++ core, Fabric is a smart choice for teams building apps across iOS, Android, and potentially desktop or web in the future. It reduces platform-specific inconsistencies and ensures the app behaves similarly everywhere.

5. Developer Tooling and Automation

Since Fabric generates native code automatically based on JavaScript declarations, it plays nicely with CI/CD pipelines in modern tooling. Teams that prioritize automation, code linting, or even custom dev tools will find it easier to plug into the development workflow.

How to Enable Fabric in Your React Native Project

Enabling the Fabric architecture in your React Native project depends on which version of React Native you are using. Starting from React Native 0.71, Fabric is opt-in and partially enabled by default in some configurations, but you still need to make a few changes to take full advantage of it.

Here’s a step-by-step guide to get you started:

1. Use the Latest Version of React Native

To work with Fabric, it’s recommended that you're on React Native 0.71 or higher. Run:

npx react-native --version

If you're on an older version, consider upgrading.

2. Enable the New Architecture

Fabric is part of the new architecture, which also includes TurboModules and JSI. To enable it:

For iOS:

Open your project’s Podfile and set the USE_FRAMEWORKS! and enable new architecture flags:

:new_architecture_enabled => true

Then run:

cd ios && pod install

For Android:

In your android/gradle.properties file, add:

newArchEnabled=true

3. Confirm It's Working

After enabling Fabric, rebuild the app:

npx react-native run-ios
# or
npx react-native run-android

Check the logs for confirmation that the new architecture is enabled. You’ll see a message like:

Running app with Fabric enabled.

4. Use Fabric-Ready Components

Currently, not all components in React Native use Fabric by default. To see the benefits of Fabric, try integrating Fabric-compatible libraries or writing custom native components using the new architecture. React Native's core team and community libraries are steadily migrating their components to support Fabric.

Note: These steps may involve some manual configuration as the new architecture continues to evolve, but tools and templates are being developed to simplify the process in future releases.

Conclusion

Fabric architecture marks a significant advancement in React Native development, making this JavaScript framework more efficient and developer-friendly. It overcame many challenges faced by the legacy architecture and introduced a more reliable, performant, and flexible foundation for modern app development.

Whether your goal is smooth UI, better integration with native modules, or scalable cross-platform performance, adopting Fabric puts your app in a stronger position. If you are planning to modernize your codebase or build a new app, collaborating with a React Native app development company can help you make the most of the Fabric architecture.