As a startup founder, one of the most critical decisions you'll make is choosing the right technology stack for your mobile app. The wrong choice can slow down development, limit scalability, and drain your resources. Two popular cross-platform solutions dominating the startup scene today are React Native and Kotlin Multiplatform Mobile (KMM).

Both offer the promise of building apps for iOS and Android using a shared codebase — but they take different approaches and come with unique advantages. In this article, we'll compare React Native and Kotlin Multiplatform across key criteria to help you decide which is best for your startup.

What Is React Native?

React Native, developed by Meta (Facebook), is a JavaScript framework that allows developers to build cross-platform mobile apps using React. It renders using native components, making it feel like a “native” app to users, while enabling a fast development cycle with one codebase.

Key Features:

• Shared UI and business logic
• Large community and rich ecosystem
• Hot reloading for fast iteration
• Easy integration with native code when needed

What Is Kotlin Multiplatform?

Kotlin Multiplatform, created by JetBrains, is a more recent approach to cross-platform development. It allows you to write shared code (mostly business logic) in Kotlin, while the UI layer remains native (SwiftUI for iOS, Jetpack Compose or XML for Android).

Key Features:

• Shared code for data, business logic, and networking
• Native UI for optimal performance and platform-specific feel
• Fully compatible with existing Kotlin and native codebases
• Backed by JetBrains and Google (for Kotlin support)

Comparison: React Native vs. Kotlin Multiplatform

When Should You Choose React Native?

React Native is an excellent choice if:

• You need to build an MVP quickly
• Your app relies more on UI than heavy background processing
• You want to reduce development cost with a shared codebase
• You plan to integrate with third-party APIs or SDKs commonly used in the JavaScript world

Startups with limited resources and time-to-market pressure can greatly benefit from React Native’s fast iteration cycle and community support.

When Should You Choose Kotlin Multiplatform?

Kotlin Multiplatform is ideal if:

• Your app requires native UI/UX and performance
• You want to reuse business logic across platforms without compromising platform-specific design
• You plan to scale the app and integrate deeply with platform-specific APIs

Startups building complex apps with custom animations, offline capability, or high-performance needs will appreciate KMM’s flexibility and native integration.

Our Take at NextStack

At NextStack, we’ve helped numerous startups and scale-ups make the right tech stack decisions. Here's what we often advise:

• React Native is perfect for startups building consumer apps, MVPs, or content-driven platforms where development speed and budget matter most.
• Kotlin Multiplatform shines for financial, logistics, or enterprise-grade apps that demand performance, scalability, and strong architecture.

Sometimes, a hybrid approach makes the most sense — using React Native to get to market, and switching to KMM or native modules as your app grows.

Final Thoughts

There’s no one-size-fits-all answer when it comes to React Native vs. Kotlin Multiplatform. It depends on your product goals, team expertise, and long-term vision. If you’re unsure, start with a technical consultation.

Need help deciding or building your app? Contact our team — we’ll help you evaluate, prototype, and launch the right way.