Maintaining two separate native codebases, one in Swift for iOS and one in Kotlin for Android, is expensive. Two teams, two deployment pipelines, two sets of bugs to fix, and features that ship on one platform weeks before the other. We have seen companies spending $400,000 or more per year on native mobile development for apps that do not need the full power of native.
React Native has matured to the point where it handles 85% of mobile app use cases without meaningful compromise. The question is not whether React Native is good enough. It is whether the migration is worth the upfront investment. For most teams we work with, the answer is yes, and the payback period is under 12 months.
When Migration Makes Sense
Not every app should be rewritten in React Native. Here is where we see the strongest case:
- Your app is primarily content, forms, and API calls. E commerce, fintech dashboards, social feeds, marketplaces, and SaaS mobile companions are all excellent candidates. We built Traderly as a cross platform app that handles real time data and complex UI without any performance issues.
- Feature parity between platforms is a constant struggle. If your iOS app is always 2 to 4 weeks ahead of Android (or vice versa), you are wasting engineering time on duplicated effort.
- You cannot hire enough native developers. Senior iOS and Android engineers are expensive and scarce. A single React Native team can ship to both platforms, and the talent pool of JavaScript and TypeScript developers is much larger.
- Your app does not rely heavily on platform specific APIs. If you are building an augmented reality app, a video editor with custom GPU shaders, or a game with complex animations, native is still the right choice.
We have a detailed comparison of React Native versus native development that goes deeper into the technical trade offs.
The Cost Math
Here is a realistic cost comparison we use when advising clients:
Native (maintaining both platforms):
- 2 to 3 iOS engineers: $300,000 to $600,000 per year
- 2 to 3 Android engineers: $300,000 to $600,000 per year
- QA across both platforms: $100,000 to $150,000 per year
- Total: $700,000 to $1,350,000 per year
React Native (single codebase):
- 2 to 4 React Native engineers: $300,000 to $700,000 per year
- QA (single platform): $80,000 to $120,000 per year
- Occasional native module work: $30,000 to $60,000 per year
- Total: $410,000 to $880,000 per year
That is a 40% to 50% reduction in ongoing development costs, every year, after the migration is complete. The migration itself typically costs between $80,000 and $250,000 depending on app complexity, which means most companies break even within the first year. For a deeper look at mobile app costs, see our full breakdown of mobile app development pricing.
The Migration Strategy
We do not recommend a big bang rewrite. That approach takes too long, introduces too much risk, and leaves your existing users without updates for months. Instead, we use a phased migration strategy.
Phase 1: New features in React Native. Start by building all new screens and features in React Native. The existing native app continues to serve users while the React Native codebase grows. This is the lowest risk starting point because you are not touching working code.
Phase 2: Shared screens migration. Identify screens that are nearly identical across iOS and Android and migrate them to React Native. Login flows, settings pages, profile screens, and list views are typically the easiest to convert because they are standard UI patterns with straightforward data fetching.
Phase 3: Core feature migration. Migrate the high value screens that represent your app's primary use case. This is where you need the most careful testing and performance validation. We benchmark every migrated screen against the native original to ensure there is no perceptible performance regression.
Phase 4: Native module bridges. For features that genuinely need native code (camera access, background processing, Bluetooth, complex animations), we write thin native modules that bridge into the React Native layer. This gives you native performance where it matters while keeping the business logic in shared TypeScript.
Phase 5: Decommission native codebases. Once all features are running in React Native, remove the old native code and simplify your CI/CD pipeline to a single build process.
Performance Reality Check
The "React Native is slow" narrative is outdated. With the New Architecture (Fabric renderer and TurboModules), React Native apps achieve near native performance for the vast majority of use cases. Here is what we measure on production apps:
- UI thread frame rate: 58 to 60 fps on modern devices, indistinguishable from native
- App startup time: 10% to 20% slower than pure native on cold start, which translates to roughly 200 to 400 milliseconds. Users do not notice.
- Memory usage: 5% to 15% higher than equivalent native apps. Rarely a problem on devices with 4GB+ RAM.
- Bundle size: React Native apps are typically 10 to 20MB larger than native equivalents due to the JavaScript runtime.
The scenarios where performance genuinely degrades are long flat lists with complex cells (thousands of items), heavy image processing, and apps that do significant work on the JavaScript thread. All of these have well established solutions: FlashList for lists, native modules for image processing, and worklets for thread offloading.
We also evaluate React Native against Flutter on every project. Our recommendation depends on your team's existing skills and the specific requirements of the app.
What Stays Native
Even in a fully migrated React Native app, some code remains native. This is by design, not a limitation:
- Push notification handling often needs native setup for background delivery
- Deep linking configuration requires native URL scheme registration
- Biometric authentication bridges to native Face ID and fingerprint APIs
- In app purchases use native StoreKit and Google Play Billing through bridge libraries
- Background tasks for data sync or location tracking run in native code
The key insight is that these native modules are small, stable, and rarely need changes. You write them once and they work across app updates. The business logic, UI, and feature development all happen in the shared React Native codebase.
Mistakes to Avoid
Trying to share 100% of the code. Aiming for 95% code sharing is realistic. Aiming for 100% leads to awkward abstractions that make both platforms worse. Allow platform specific code where it genuinely improves the user experience.
Ignoring navigation architecture. React Navigation and native navigation have different mental models. Migrating screens without rethinking the navigation structure leads to janky transitions and inconsistent behavior. Design the navigation graph upfront.
Skipping automated testing during migration. Every migrated screen needs automated tests that verify it matches the behavior of the native original. We write end to end tests with Detox before decommissioning any native code.
Not investing in your CI/CD pipeline. A React Native app that still requires manual builds and deployments will not deliver on the efficiency promise. We set up automated builds, over the air updates via CodePush or EAS, and automated app store submissions as part of every migration.
Making the Decision
If you are spending more than $500,000 per year on dual native teams and your app does not require heavy platform specific features, the migration will pay for itself. The upfront cost is real, but the ongoing savings compound every year.
We build and migrate mobile apps for companies at every stage. If you are considering the move to React Native and want an honest assessment of whether it makes sense for your specific app, reach out to us.