React Native's Bridge Retirement: Why JSI Matters for 2026 Apps

React Native’s evolution took a major leap forward in 2026 when the framework permanently retired its legacy JSON-based native bridge. This long-anticipated transition replaced asynchronous communication with the JavaScript Interface (JSI), a groundbreaking architecture that enables direct memory access between JavaScript and native code. The change eliminates the performance bottlenecks that historically plagued cross-platform apps, particularly in graphics-heavy or computationally intensive tasks.

The Legacy Bridge: A Bridge Too Far?

Before JSI, React Native relied on a three-step process to facilitate communication between JavaScript and native platforms like iOS and Android. The workflow began with JavaScript converting actions or data into JSON strings, which were then sent asynchronously across the bridge. On the native side, these JSON payloads required deserialization before platform-specific actions—like rendering UI elements or accessing hardware features—could be executed. This method introduced significant latency, especially in real-time applications such as games or augmented reality.

Custom native modules were often necessary to extend React Native’s capabilities beyond its built-in APIs. Developers typically turned to Native Modules or UI Components in scenarios such as:

• Accessing unsupported hardware, including advanced camera sensors or biometric systems like Face ID and fingerprint scanners
• Integrating third-party SDKs that only provided iOS CocoaPods or Android Gradle dependencies
• Reusing existing native code during migrations from older apps
• Performing high-performance tasks like image processing or audio manipulation
• Implementing custom UI layouts that couldn’t be fully replicated with React Native’s standard components

While functional, this bridge-based approach created friction. The serialization and deserialization steps added overhead, and the asynchronous nature meant JavaScript couldn’t directly call native methods without waiting for a response.

The JSI Revolution: Synchronous Execution Without the Middleman

The shift to JSI began experimentally with React Native 0.68 in March 2022, marking the introduction of the New Architecture. This overhaul introduced TurboModules and the Fabric renderer, both of which leveraged JSI to enable direct C++ memory references between JavaScript and native code. The result? Synchronous execution that bypasses JSON serialization entirely, delivering near-instantaneous communication.

The transition wasn’t abrupt. React Native maintained backward compatibility through several milestones:

• React Native 0.73 (Late 2023): Introduced a “bridgeless mode” as an experimental opt-in feature, allowing developers to test JSI-based workflows.
• React Native 0.76 (October 2024): Made the New Architecture the default for new projects, while preserving an interoperability layer for legacy bridge-based modules.
• React Native 0.82 (October 2025): Disabled the old architecture permanently by removing toggle flags, making JSI mandatory for all builds.
• React Native 0.85 (April 2026): Removed the legacy bridge code entirely, eliminating any fallback mechanisms.

With React Native 0.85, the JSON bridge is no longer an option. Projects built on this version must use TurboModules and Fabric Components, which rely on JSI for direct, synchronous execution.

What’s Lost and What Replaces It

The retirement of the JSON bridge isn’t just a technical change—it’s a fundamental shift in how React Native apps are developed. Here’s what developers need to know about the transition:

❌ What’s Gone:

• The ability to use legacy bridge modules like RCTBridgeModule (iOS) or ReactContextBaseJavaModule (Android) to pass JSON data asynchronously
• The interoperability layer that allowed old bridge-based code to run on newer React Native versions
• The option to opt out of the New Architecture via configuration flags

✅ What’s Required Now:

• Writing Turbo Native Modules, which provide synchronous access to native methods through JSI
• Building Fabric Components for custom UI rendering that integrates seamlessly with React Native’s reconciler
• Updating third-party libraries to ensure compatibility with the New Architecture; unupdated packages may crash or fail to build in React Native 0.85+ and later

For app developers, this means revisiting any legacy native modules in your codebase and rewriting them to conform to the TurboModules standard. The good news? The performance gains are substantial. Tasks that once required asynchronous callbacks now execute instantly, reducing UI lag and improving overall responsiveness.

The Ripple Effect on the Ecosystem

The retirement of the JSON bridge has sent shockwaves through the React Native ecosystem. Developers maintaining apps on older versions face a critical choice: migrate now or risk being left behind as the framework continues to evolve. Third-party library maintainers are under pressure to update their packages, with many already releasing JSI-compatible versions.

For teams still relying on legacy bridge code, the migration process isn’t trivial. It requires:

• Rewriting native modules to use TurboModules
• Updating build configurations and dependencies
• Testing thoroughly to ensure no regressions in functionality or performance

Despite the challenges, the move to JSI is a net positive for the React Native community. It future-proofs the framework, aligns it with modern performance expectations, and simplifies the mental model for developers. By eliminating the bridge, React Native has reduced complexity and removed a long-standing source of bugs and performance issues.

As React Native continues to mature, the lessons learned from the JSON bridge’s retirement will shape the framework’s future. Developers who understand both the legacy architecture and the New Architecture will be better equipped to build high-performance, cross-platform apps that leverage the full power of native platforms—without the overhead of a middleman.