React Native Migration: New Architecture 2026 Guide

Published: February 23, 2026 | Reading Time: 20 minutes

About the Author

Nirmalraj R is a Full-Stack Developer at AgileSoftLabs, specializing in MERN Stack and mobile development, focused on building dynamic, scalable web and mobile applications.

Key Takeaways

• Migration is now mandatory: React Native 0.76 makes New Architecture the default; version 0.82 permanently disables the old architecture
• Four core pillars: JSI (JavaScript Interface), TurboModules, Fabric renderer, and Codegen form the foundation of the New Architecture
• Dramatic performance gains: 43% faster cold starts, 39% rendering improvements, 20–30% memory reduction, and 40x faster native communication
• Migration timeline: 2–8 weeks depending on project complexity and custom native code volume
• Critical prerequisites: React Native 0.76+, Hermes engine enabled, dependency audit completed before starting
• Custom native code requires most effort: Migrating custom native modules to TurboModules and Fabric components takes 70% of migration time
• Community support is strong: Major packages (React Navigation, Reanimated, Gesture Handler) fully support New Architecture as of 2026
• Performance testing is essential: Measure cold start time, memory usage, and rendering speed before and after to validate improvements

Introduction: Why Migration Is No Longer Optional

2026 marks a watershed moment for React Native development. The New Architecture—featuring Fabric, TurboModules, and JSI—is no longer optional. With React Native 0.76 making it the default and version 0.82 permanently disabling the old architecture, every React Native team faces a critical decision: migrate now or face mounting technical debt as community packages drop legacy support.

This isn't just another framework update. The New Architecture represents a fundamental reimagining of how React Native communicates between JavaScript and native code. Early adopters report cold start time improvements of 43%, rendering speed boosts of 39%, and memory usage reductions of 20–30%. If you're building production-grade applications, migration is no longer a question of "if" but "when."

At AgileSoftLabs, we've successfully migrated dozens of production React Native apps to the New Architecture since 2023. Our team has navigated the complexities of TurboModule conversion, Fabric component migration, and third-party dependency updates across apps serving millions of users. This comprehensive guide distills those lessons into an actionable migration roadmap. Explore our mobile app development services to see how we help teams modernize their React Native applications.

Understanding the New Architecture Components

Before diving into migration, you need to understand what you're migrating to. The New Architecture consists of four core pillars that work together to eliminate the performance bottlenecks of the old bridge-based system.

1. JSI (JavaScript Interface): The Foundation

JSI is a lightweight C++ API that replaces the asynchronous JSON-based bridge with direct, synchronous communication between JavaScript and native code. Instead of serializing data to JSON, queueing it on the bridge, and deserializing it on the other side, JSI enables direct function invocation.

Key Benefit: JSI eliminates the serialization overhead that caused the old bridge to become a bottleneck. Native modules can now expose functions directly to JavaScript, and JavaScript can hold references to native objects.

// Example: Old Bridge (async, serialized)
// JS → JSON → Native Thread → Process → JSON → JS
NativeModules.DatabaseModule.query('SELECT * FROM users')
  .then(result => console.log(result));

// New Architecture with JSI (sync, direct)
// JS → Direct C++ Call → Native → Return
const result = global.DatabaseModule.querySync('SELECT * FROM users');
console.log(result);

2. TurboModules: Lazy-Loaded Native Modules

TurboModules replace the old NativeModules system with on-demand initialization. In the old architecture, every native module was initialized at app startup—even if never used. An app with 50 native modules might only need 5 during the first interaction, but all 50 were loaded anyway.

TurboModules load only when accessed, dramatically improving startup time. They're also type-safe through Codegen, catching mismatches at build time instead of runtime.

3. Fabric: The New Rendering System

Fabric is the new UI rendering layer that replaces the old UIManager/ViewManager model. It unifies rendering logic across platforms using a shared C++ core, enabling several game-changing capabilities:

• Synchronous layout calculation: No more async layout thrashing
• Priority-based rendering: High-priority updates can interrupt low-priority renders
• Concurrent rendering support: Full React 18 features like Suspense and Transitions
• Type-safe props: Compile-time validation of component properties

4. Codegen: Type-Safe Native Bindings

Codegen is the build-time tool that generates type-safe glue code between JavaScript and native platforms. You define TypeScript or Flow interfaces once, and Codegen produces the boilerplate for iOS (Objective-C++), Android (C++/Kotlin), and JavaScript.

This eliminates entire classes of bugs—type mismatches, missing null checks, incorrect method signatures—by catching them during compilation rather than in production.

For businesses requiring expert React Native architecture and implementation, our custom software development services provide end-to-end support from migration planning to performance optimization.

Pre-Migration Audit Checklist

Before changing a single line of code, you need a comprehensive understanding of your project's readiness for migration. This audit will save you weeks of troubleshooting.

Step 1: Check React Native Version

# Check current React Native version
npx react-native --version

# Expected output for New Architecture support:
# React Native CLI: 2.x.x
# React Native: 0.76.0 or higher

# If below 0.76, upgrade first:
npm install react-native@latest

Step 2: Audit Dependencies for Compatibility

Not all packages support the New Architecture yet. Create a dependency compatibility report:

# List all native dependencies
npm list --depth=0 | grep react-native

# Check each package's New Architecture support
# Look for keywords: "Fabric", "TurboModules", "New Architecture"
npm info react-native-reanimated
npm info react-native-screens
npm info @react-navigation/native

Create a spreadsheet tracking each dependency:

Step 3: Inventory Custom Native Modules

Identify all custom native code that needs migration:

# Find custom native modules (iOS)
find ios/ -name "*Bridge*" -o -name "RCT*"

# Find custom native modules (Android)
find android/ -name "*Module.java" -o -name "*Package.java"

# List JavaScript files that import NativeModules
grep -r "NativeModules" src/ --include="*.js" --include="*.ts" --include="*.tsx"

Migration Effort Estimates:

Step 4: Verify Hermes Engine

The New Architecture requires Hermes. Check if it's enabled:

// Add this to your app's root component temporarily
import { Platform } from 'react-native';

console.log('Hermes enabled:', !!global.HermesInternal);

// iOS: Check ios/Podfile
// Should contain: :hermes_enabled => true

// Android: Check android/app/build.gradle
// Should contain: enableHermes: true

! Warning: If Hermes isn't enabled, enable it before proceeding. The New Architecture is built on Hermes's JSI capabilities and won't work with JavaScriptCore.

Explore our case studies to see successful New Architecture migrations across fintech, healthcare, and e-commerce applications.

Step-by-Step Migration Process

With your audit complete, you're ready to begin the actual migration. This process follows a specific sequence to minimize breakage and enable incremental testing.

Phase 1: Enable New Architecture in Your Project

Starting with React Native 0.76, the New Architecture is enabled by default. However, if you're on an earlier version or need to verify configuration:

iOS Configuration:

# ios/Podfile

require_relative '../node_modules/react-native/scripts/react_native_pods'
require_relative '../node_modules/@react-native-community/cli-platform-ios/native_modules'

platform :ios, '13.0'

target 'YourApp' do
  config = use_native_modules!

  use_react_native!(
    :path => config[:reactNativePath],
    :hermes_enabled => true,
    :fabric_enabled => true,
  )

  post_install do |installer|
    react_native_post_install(installer)
  end
end

# Reinstall pods with New Architecture
cd ios
pod deintegrate
pod install
cd ..

Android Configuration:

# android/gradle.properties

# Enable Hermes
hermesEnabled=true

# Enable New Architecture
newArchEnabled=true

# Enable TurboModules
TM_ENABLED=true

# Enable Fabric
FABRIC_ENABLED=true

// android/app/build.gradle
// File: android/app/build.gradle

android {
    defaultConfig {
        // ... other config
        
        // Ensure this is present for Codegen
        buildConfigField("boolean", "IS_NEW_ARCHITECTURE_ENABLED", 
            isNewArchitectureEnabled().toString())
    }
}

// Verify Hermes is enabled
project.ext.react = [
    enableHermes: true,
    enableNewArchitecture: true
]

Phase 2: Run Codegen

Codegen runs automatically during the build process, but you should verify it's working correctly:

# iOS: Codegen output is in ios/build/generated/ios
# Android: Codegen output is in android/app/build/generated/source/codegen

# Force a clean build to trigger Codegen
npm run ios -- --reset-cache
npm run android -- --reset-cache

# Check Codegen output
ls -la ios/build/generated/ios/
ls -la android/app/build/generated/source/codegen/

Tip: If Codegen isn't generating files, check for TypeScript errors in your spec files. Codegen fails silently if it can't parse your type definitions.

Phase 3: Migrate Custom Native Modules to TurboModules

This is where you'll spend most of your migration time. Here's a complete example of converting a legacy native module to a TurboModule.

Example: Analytics Module Migration

Step 1: Define the TypeScript Spec

// File: src/specs/NativeAnalytics.ts

import type { TurboModule } from 'react-native';
import { TurboModuleRegistry } from 'react-native';

export interface Spec extends TurboModule {
  // Synchronous methods
  logEvent(eventName: string, properties?: Object): void;
  setUserId(userId: string): void;
  
  // Asynchronous methods (return Promise)
  getSessionId(): Promise<string>;
  getUserId(): Promise<string | null>;
  
  // Methods with callbacks
  trackScreenView(
    screenName: string,
    callback: (success: boolean) => void
  ): void;
}

export default TurboModuleRegistry.getEnforcing<Spec>('Analytics');

Step 2: Create JavaScript Wrapper

// File: src/Analytics.ts

import NativeAnalytics from './specs/NativeAnalytics';

class Analytics {
  logEvent(eventName: string, properties?: Record<string, any>): void {
    if (!eventName || typeof eventName !== 'string') {
      throw new Error('Event name must be a non-empty string');
    }
    NativeAnalytics.logEvent(eventName, properties || {});
  }

  setUserId(userId: string): void {
    if (!userId) {
      throw new Error('User ID cannot be empty');
    }
    NativeAnalytics.setUserId(userId);
  }

  async getSessionId(): Promise<string> {
    return NativeAnalytics.getSessionId();
  }
}

export default new Analytics();

Step 3: Register the Package

// File: android/app/src/main/java/com/yourapp/MainApplication.java

@Override
protected List<ReactPackage> getPackages() {
  List<ReactPackage> packages = new PackageList(this).getPackages();
  // Add your custom package
  packages.add(new AnalyticsPackage());
  return packages;
}

Phase 4: Migrate Native UI Components to Fabric

If you have custom native UI components, they need to be migrated to Fabric. Here's a complete example of a custom view component. When working with experienced React Native developers, this process can be accelerated significantly. 

Example: Custom Gradient View Component

// File: src/specs/NativeGradientViewNativeComponent.ts

import type { ViewProps } from 'react-native';
import type { HostComponent } from 'react-native';
import type { ColorValue } from 'react-native';
import codegenNativeComponent from 'react-native/Libraries/Utilities/codegenNativeComponent';

interface NativeProps extends ViewProps {
  colors?: ReadonlyArray<ColorValue>;
  startPoint?: { x: number; y: number };
  endPoint?: { x: number; y: number };
  angle?: number;
  onGradientReady?: (event: { 
    nativeEvent: { ready: boolean } 
  }) => void;
}

export default codegenNativeComponent<NativeProps>(
  'GradientView'
) as HostComponent<NativeProps>;

// File: src/GradientView.tsx

import React from 'react';
import { ViewProps, processColor } from 'react-native';
import NativeGradientView from './specs/NativeGradientViewNativeComponent';

export interface GradientViewProps extends ViewProps {
  colors?: string[];
  startPoint?: { x: number; y: number };
  endPoint?: { x: number; y: number };
  angle?: number;
  onGradientReady?: (ready: boolean) => void;
}

export const GradientView: React.FC<GradientViewProps> = ({
  colors = ['#4c669f', '#3b5998', '#192f6a'],
  startPoint = { x: 0, y: 0 },
  endPoint = { x: 1, y: 1 },
  angle = 0,
  onGradientReady,
  ...rest
}) => {
  const processedColors = React.useMemo(
    () => colors.map(color => processColor(color)),
    [colors]
  );

  const handleGradientReady = React.useCallback(
    (event: { nativeEvent: { ready: boolean } }) => {
      onGradientReady?.(event.nativeEvent.ready);
    },
    [onGradientReady]
  );

  return (
    <NativeGradientView
      {...rest}
      colors={processedColors}
      startPoint={startPoint}
      endPoint={endPoint}
      angle={angle}
      onGradientReady={handleGradientReady}
    />
  );
};

export default GradientView;

// File: ios/GradientView.h

#import <React/RCTViewComponentView.h>
#import <UIKit/UIKit.h>

@interface GradientView : RCTViewComponentView
@end

# Update core navigation packages
npm install @react-navigation/native@^6.0.0
npm install @react-navigation/native-stack@^6.0.0
npm install react-native-screens@^3.30.0
npm install react-native-safe-area-context@^4.8.0

# Update animation libraries
npm install react-native-reanimated@^3.8.0
npm install react-native-gesture-handler@^2.15.0

# Update other common packages
npm install react-native-vector-icons@^10.0.0
npm install @react-native-async-storage/async-storage@^1.21.0

# Rebuild iOS
cd ios && pod install && cd ..

# Clean Android build
cd android && ./gradlew clean && cd ..

// Add to your App.tsx or index.js for debugging
if (__DEV__) {
  console.log('New Architecture enabled:', global.nativeFabricUIManager != null);
  console.log('TurboModules enabled:', global.__turboModuleProxy != null);
  console.log('Hermes enabled:', global.HermesInternal != null);
}

Test Checklist
Startup Performance: Measure cold start time before and after
Native Module Calls: Test all custom native module functions
Animations: Verify smooth 60fps animations, especially with Reanimated
Navigation: Test all navigation flows, especially deep linking
Forms and Inputs: Check keyboard handling and input focus
Memory Usage: Profile memory with heavy list scrolling
Crash Reports: Monitor crash analytics for New Architecture-specific issues

For comprehensive React Native development and migration expertise, our web application development services encompass full-stack mobile solutions with modern architectural patterns.

Common Migration Pitfalls and Solutions

Pitfall 1: Codegen Not Running

Symptom: Build succeeds but TurboModules aren't loaded. No generated files in build/generated directory.

Solution:

// Ensure package.json has the correct Codegen configuration
{
  "name": "your-library",
  "version": "1.0.0",
  "codegenConfig": {
    "name": "RNYourLibrarySpec",
    "type": "all",
    "jsSrcsDir": "src/specs",
    "android": {
      "javaPackageName": "com.yourcompany.yourlibrary"
    }
  }
}

Pitfall 2: Type Mismatches Between JS and Native

Solution: Always use exact type definitions in your spec files:

// BAD: Generic Object type
export interface Spec extends TurboModule {
  processData(data: Object): void; // Too vague
}

// GOOD: Specific interface
export interface UserData {
  id: string;
  name: string;
  age: number;
  metadata?: { [key: string]: string };
}

export interface Spec extends TurboModule {
  processData(data: UserData): void;
}

Pitfall 3: Synchronous Methods Blocking UI Thread

Symptom: UI freezes when calling certain TurboModule methods.

Solution: Only use synchronous methods for truly fast operations. For anything taking more than a few milliseconds, use Promises:

// BAD: Synchronous method for slow operation
export interface Spec extends TurboModule {
  parseHugeFile(filePath: string): string; // Can block for seconds
}

// GOOD: Async method for slow operation
export interface Spec extends TurboModule {
  parseHugeFile(filePath: string): Promise<string>; // Won't block UI
}

Performance Benchmarks: Before vs After

Real-world performance improvements from production migrations in 2025–2026. These benchmarks come from teams who have completed New Architecture migrations and are part of successful custom software development projects.

How to Measure Performance in Your App

// Performance monitoring utility
import { PerformanceObserver } from 'react-native-performance';

// Measure app startup time
const startupObserver = new PerformanceObserver((list) => {
  const entries = list.getEntries();
  entries.forEach((entry) => {
    console.log(`${entry.name}: ${entry.duration}ms`);
  });
});

startupObserver.observe({ entryTypes: ['measure'] });

For detailed performance optimization strategies and monitoring implementation, explore our product portfolio featuring performance analytics solutions for mobile applications.

Compatibility Checklist: Popular Libraries

This table reflects New Architecture compatibility status as of February 2026:

Pro Tip: Before starting migration, run npm outdated to see which of your dependencies have New Architecture-compatible versions available.

Conclusion: The New Architecture Is the Future

2026 marks the end of the transition period for React Native. The New Architecture is no longer experimental or optional—it's the only path forward. Apps still running on the old architecture face mounting technical debt as community packages drop legacy support and security updates stop flowing to older React Native versions.

The performance gains are undeniable: cold start times cut by 43%, rendering speeds increased by 39%, memory usage reduced by 26%, and JavaScript-to-native communication accelerated by 40x. These aren't theoretical improvements—they're real-world results from production migrations.

Yes, migration requires investment. Depending on your app's complexity, you're looking at anywhere from a few days to several weeks of development time. But the alternative—staying on deprecated architecture—means slower performance, incompatibility with new packages, and eventually, being unable to upgrade React Native at all.

The migration path is well-documented and the community has already solved most common problems. Follow the systematic approach outlined in this guide: audit your dependencies, enable the New Architecture flags, migrate custom native modules to TurboModules, convert native components to Fabric, and test thoroughly.

Ready to Migrate to React Native's New Architecture?

Expert Migration Services

At AgileSoftLabs, we specialize in React Native New Architecture migrations, helping teams achieve 40%+ performance improvements without disrupting users. Our team has successfully migrated dozens of production apps—from small startups to enterprise applications serving millions of users.

What We Deliver:

• Complete pre-migration audit and dependency compatibility analysis
• Custom native module migration to TurboModules
• Fabric component conversion for UI elements
• Performance optimization and benchmarking
• Third-party package updates and compatibility fixes
• Comprehensive testing and quality assurance

Get a Free Migration Assessment

Contact our team to schedule a technical consultation. We'll assess your React Native app, provide a detailed migration roadmap, and deliver timeline and cost estimates based on your specific architecture.

For more insights on React Native development, mobile performance optimization, and cross-platform best practices, visit our blog for the latest technical guides and industry trends.

Frequently Asked Questions

1. What React Native version is required for New Architecture migration?

Minimum React Native 0.76, recommended 0.82+ with Hermes V1. Xcode 15+ for iOS, Android Studio Hedgehog with Kotlin 1.9+. Node 20 LTS, CocoaPods 1.15+.

2. How long does a typical New Architecture migration take?

Phase 1-2 (audit/update): 2-4 weeks. Phase 3 (TurboModules): 4-8 weeks. Phase 4 (rollout): 4 weeks. Shopify completed two apps in 12 weeks total.

3. What are the first steps to prepare for migration?

Run React Native Upgrade Helper between current/target versions. Update tooling (Xcode, Android Studio, Node). Audit third-party libraries for New Arch compatibility using React Native Directory filter.

4. Which libraries break with New Architecture enabled?

Native modules without TurboModule specs. UI components not Fabric compatible. Check React Native Directory "Supports New Architecture" filter. 90% core modules work as of 2024.

5. How do you enable New Architecture in development builds?

iOS: RCT_NEW_ARCH_ENABLED=1 in Podfile, pod install. Android: newArchEnabled=true in gradle.properties. Use feature flags for gradual rollout starting at 8% users.

6. What performance gains come from New Architecture?

Synchronous layout, concurrent React 18 features, faster startup via lazy TurboModules. Shopify reported 20-30% faster cold starts, smoother 60fps animations.

7. Can you maintain feature development during migration?

Yes—use feature flags. Ship New Arch code behind toggles. Dual build configurations let engineers work either architecture locally. Shopify shipped weekly releases throughout.

8. How do you migrate custom native modules to TurboModules?

Add TypeScript spec file. Implement getConstants, getEventEmitter. Replace NativeModules with TurboModuleRegistry. Simple modules convert in 1 day, complex take 1-2 weeks.

9. What's the rollback plan if migration fails?

Interoperability layer runs old/new modules together. Toggle feature flag off instantly. Keep legacy build pipeline active. Shopify maintained 100% rollback capability.

10. Is New Architecture migration mandatory for React Native apps?

Effectively yes by 2026. Legacy architecture stops major features. React 18+ concurrent features require it. Most libraries dropping legacy support in 2026.