Kotlin Multiplatform vs React Native: Which Cross-Platform Framework Should You Choose? 🤔

Hey devs! 👋

So you’re trying to pick a cross-platform framework and you’re stuck between React Native and Kotlin Multiplatform (KMP)? Been there, done that, got the stack overflow tabs to prove it 😅

I’ve been on this journey from React web dev → React Native → native Android with Kotlin → and now KMP. Trust me, I’ve felt the pain and glory of each approach. Let me break down what I’ve learned so you don’t have to make the same mistakes I did.

TL;DR for the Impatient Devs 🏃‍♂️

React Native: Great for web devs, fast prototyping, huge ecosystem. JavaScript bridge can be… spicy 🌶️ Kotlin Multiplatform: Share business logic only, native UI, better performance. Steeper learning curve, smaller ecosystem.

But stick around for the juicy details because the devil’s in the implementation!

My Developer Journey (Or: How I Learned to Stop Worrying and Love Mobile) 📱

Started as a React dev (like half of us, let’s be real). React Native felt like the obvious choice - same language, similar patterns, “learn once, write anywhere” they said. It’ll be fun, they said 🤡

Plot twist: It was actually pretty fun! Until it wasn’t.

Then I dove into native Android development with Kotlin and holy moly, the performance difference was chef’s kiss 👨‍🍳💋. But maintaining two codebases? My soul was crying.

Enter Kotlin Multiplatform. Mind = blown 🤯

React Native: The Good, Bad, and the “Why is This Happening?”

The Good Stuff ✅

JavaScript Familiarity: If you’re coming from web dev, RN feels like home. Same old JS, familiar React patterns, even similar debugging tools.

Rapid Development: Want to prototype something fast? RN is your friend. Hot reload is actually hot, and you can iterate stupidly fast.

Ecosystem is MASSIVE: Need a library? There’s probably 5 of them. Need a weird edge case solution? Someone on Stack Overflow already solved it 3 years ago.

Single Codebase: Write once, deploy to iOS and Android. The dream, right? Well… mostly 😬

The Not-So-Good Stuff ❌

The Bridge: That JavaScript-to-native bridge? It’s like having a translator who sometimes just makes stuff up. Performance bottlenecks are real, especially with complex animations or heavy data processing.

Platform Differences: “Write once, run anywhere” becomes “write once, debug everywhere” real quick. iOS and Android have different behaviors, and you’ll spend time handling platform-specific edge cases.

Native Module Dependency: Need something the core RN doesn’t provide? Hope there’s a good community module, or you’re writing native code anyway.

Bundle Size: Your app size can get chunky. Users with older phones or limited storage aren’t always happy.

When React Native Shines 🌟

Perfect for:

• MVPs and prototypes
• Apps that are mostly CRUD operations
• Teams with strong React/JS background
• Startups that need to move fast
• Apps that don’t need heavy native features

Native Android with Kotlin: The Performance Beast 🦍

The Good Stuff ✅

Performance: It’s native, baby! No bridge, no translation layer, just pure compiled code running on the metal.

Platform Features: Want to use the latest Android API? It’s there day one. Camera2 API? Motion sensors? Background processing? All available without waiting for someone to write a bridge.

Tooling: Android Studio is legitimately good. The debugger actually works, profiling tools are built-in, and the emulator doesn’t make you want to throw your laptop.

Type Safety: Kotlin’s null safety and type system catch so many bugs at compile time. It’s like having a really pedantic code reviewer who’s actually helpful.

The Not-So-Good Stuff ❌

Two Codebases: Want iOS too? That’s a whole separate Swift/Objective-C codebase to maintain. Your velocity just got cut in half.

Learning Curve: If you’re coming from web dev, the Android lifecycle, Gradle, and Kotlin syntax can be overwhelming at first.

Development Speed: Native development is typically slower than cross-platform for getting something working on both platforms.

When Native Android is the Move 💪

Perfect for:

• Performance-critical apps (games, media processing, complex animations)
• Apps that heavily use platform-specific features
• Long-term projects where maintenance matters more than speed to market
• When you need that buttery smooth 60fps experience

Kotlin Multiplatform: The Best of Both Worlds? 🌍

Now here’s where it gets interesting. KMP isn’t trying to be React Native. It’s taking a different approach entirely.

The Philosophy Shift 🧠

Instead of “write UI once, run everywhere,” KMP says “share your business logic, keep native UI.”

Your networking, data processing, business rules, validation - all that lives in shared Kotlin code. Your UI stays native on each platform.

The Good Stuff ✅

Gradual Adoption: You can start small. Share just your API client, or just your data models. No need to rewrite everything.

Native Performance: UI is native, shared code compiles to native. No JavaScript bridge tax.

Type Safety Everywhere: Kotlin’s type system works across platforms. Your iOS Swift code gets the same type safety benefits.

Growing Fast: Google’s pushing hard on this. The tooling is improving rapidly, and big companies (Netflix, Cash App, etc.) are adopting it.

Familiar Territory: If you know Kotlin, you’re 80% there. If you know Java, you can pick up Kotlin pretty quickly.

The Not-So-Good Stuff ❌

Learning Curve: You need to understand both platforms. Want iOS? You’re writing Swift UI code. Android? Compose or Views.

Ecosystem: Still smaller than RN. Some things you’ll need to implement yourself or wait for community solutions.

Tooling: Getting better, but not as mature as RN. Debugging shared code can be tricky sometimes.

Mental Model: It’s a different way of thinking about cross-platform development. Takes some adjustment.

When KMP Makes Sense 🎯

Perfect for:

• Teams that want native performance but shared business logic
• Long-term projects where code quality matters
• Apps with complex business logic but relatively standard UI
• Teams willing to invest in learning both platforms
• When you want the benefits of cross-platform without the compromises

The Real Talk: Performance Comparison 📊

Let me be straight with you about performance:

React Native: Good enough for most apps. Instagram uses it, so it can’t be that bad, right? But complex animations and heavy data processing can stutter.

Native Kotlin: Blazing fast. If your app needs to process video, handle complex animations, or work with large datasets, native is king.

KMP: Business logic performs like native (because it is native). UI performs like native (because it is native). You get the best of both worlds.

Developer Experience: My Honest Take 👨‍💻

React Native DX: 8/10 - Hot reload is amazing, debugging is familiar, huge community means solutions are everywhere.

Native Android DX: 7/10 - Great tooling, but managing two codebases hurts. Android Studio is solid though.

KMP DX: 7/10 currently, trending upward - Still rough edges, but when it works, it works really well. The shared code debugging experience is getting better.

The Ecosystem Battle 📚

React Native: Mature AF. Whatever you need, it probably exists. Package quality varies, but there’s usually something.

KMP: Growing fast but still small. You might need to write some stuff yourself, but the core libraries are solid.

Native: Platform libraries are obviously there, but you’re managing dependencies for two platforms.

Code Examples (Because We’re Devs, Not Philosophers) 💻

Data Model in React Native

interface User {
	id: string;
	name: string;
	email: string;
}

const fetchUser = async (id: string): Promise<User> => {
	const response = await fetch(`/api/users/${id}`)
	return response.json()
}

Same Data Model in KMP (Shared Code)

@Serializable
data class User(
    val id: String,
    val name: String,
    val email: String
)

class UserRepository {
    suspend fun fetchUser(id: String): User {
        return httpClient.get("/api/users/$id").body()
    }
}

The KMP version runs natively on both platforms, gives you compile-time safety, and your business logic is shared. The UI code stays native on each platform.

My Recommendation: It Depends™ 🤷‍♂️

I know, I know, “it depends” is the most developer answer ever. But hear me out:

Choose React Native if:

• You’re a small team/startup that needs to move fast
• Your team is primarily web developers
• You’re building a standard CRUD app
• Time to market is more important than performance optimization
• You need to prototype quickly

Choose Native Android (+ iOS) if:

• Performance is critical
• You’re building something platform-specific
• You have separate mobile teams for each platform
• Budget and timeline allow for maintaining two codebases

Choose Kotlin Multiplatform if:

• You want to share business logic but keep native UI
• Performance matters but you still want code sharing benefits
• You’re planning a long-term project
• Your team is willing to learn both platforms
• You want type safety across your entire mobile stack

The Future is Multiplatform (Probably) 🔮

Hot take: I think KMP is the future for serious mobile development. Here’s why:

1. Google’s all-in: They’re betting big on this
2. Industry adoption: Big players are moving to KMP
3. It solves real problems: You get performance without sacrificing code sharing
4. The tooling is catching up fast

But React Native isn’t going anywhere. It’s perfect for certain use cases and has a massive community.

My Current Stack 🛠️

For new projects, I’m choosing KMP. The shared business logic + native UI approach just makes sense for the long term. Performance is better, type safety is amazing, and I can still move reasonably fast.

But if I needed to ship an MVP yesterday? React Native all the way.

Wrapping Up 🎬

Look, there’s no perfect framework. React Native gets you there fast but with some performance trade-offs. Native gives you everything but costs more time and money. KMP is the new kid that’s trying to solve the trade-offs, and it’s getting really good at it.

My advice? Start with what your team knows, but keep learning. The mobile development landscape is evolving fast, and the best developers are the ones who can adapt.

What’s your experience been? Are you team RN, team native, or are you drinking the KMP Kool-Aid like me? Drop a comment and let me know!

If this helped you make a decision (or just procrastinate making one), give it a share! And if you’re hiring React/Kotlin/KMP developers who’ve been through the trenches… well, my DMs are open 😉

Tags: #ReactNative #KotlinMultiplatform #MobileDevelopment #CrossPlatform #Kotlin #JavaScript #NativeDevelopment