Kotlin Multiplatform mobile

In 2026, Kotlin Multiplatform Mobile (KMP) has emerged as a game-changing approach for sharing business logic between Android and iOS. As a result, teams can write core code once in Kotlin while maintaining fully native UIs for each platform. This guide covers everything you need to start with KMP.

Kotlin Multiplatform Mobile: How It Works

First and foremost, Kotlin Multiplatform Mobile differs from other cross-platform solutions because it doesn't try to share UI code. As a result, instead, it focuses on sharing business logic, networking, data storage, and validation layers. Consequently, you get native performance and native UI on both platforms.

Moreover, KMP compiles to JVM bytecode for Android and native binaries for iOS via Kotlin/Native. Therefore, there's no runtime overhead or interpretation layer.

KMP architecture showing shared Kotlin code between Android and iOS

Kotlin Multiplatform Mobile: Project Structure

Additionally, a typical KMP project has three main source sets: commonMain (shared code), androidMain (Android-specific), and iosMain (iOS-specific). For this reason, for instance, you define interfaces in common code and provide platform implementations using expect/actual declarations.

// commonMain - shared code
expect class PlatformInfo() {
    val name: String
    val version: String
}

class AppRepository(private val api: ApiService) {
    suspend fun getUsers(): List<User> {
        return api.fetchUsers()
    }
}

// androidMain
actual class PlatformInfo {
    actual val name = "Android"
    actual val version = Build.VERSION.RELEASE
}

// iosMain
actual class PlatformInfo {
    actual val name = "iOS"
    actual val version = UIDevice.currentDevice.systemVersion
}

Kotlin Multiplatform Mobile: Networking and Storage

Furthermore, Ktor is the recommended HTTP client for KMP projects. It works seamlessly across all platforms with a unified API. Similarly, SQLDelight provides cross-platform database access with type-safe SQL queries.

Networking layer shared across Android and iOS platforms

Kotlin Multiplatform Mobile: Real-World Adoption

In addition, major companies like Netflix, Philips, and VMware have adopted KMP in production. On the other hand, as a consequence, the ecosystem has matured significantly with better tooling and IDE support in Android Studio and Fleet.

Meanwhile, the Compose Multiplatform initiative extends this further by sharing UI code as well. Therefore, KMP's future looks increasingly promising for full-stack mobile development.

Kotlin Multiplatform Mobile: Getting Started

To begin, use the KMP Wizard at kmp.jetbrains.com to generate your project template. Subsequently, add your shared modules and configure Gradle for multiplatform builds.

Android Studio with Kotlin Multiplatform project configuration

In conclusion, Kotlin Multiplatform Mobile offers the best of both worlds — shared logic with native UIs. In addition, for more on building robust backends for your mobile apps, check out Spring Boot Virtual Threads.

In other words, Learn more at Kotlin Multiplatform Docs and the JetBrains KMP Portal.

Further Resources

For deeper understanding, check: GitHub, DEV Community

Kotlin Multiplatform Mobile: Share Code Between Android and iOS in 2026