Multiplatform projects are in Alpha. Language features and tooling may change in future Kotlin versions.
Support for multiplatform programming is one of Kotlin’s key benefits. It reduces time spent writing and maintaining the same code for different platforms while retaining the flexibility and benefits of native programming. Learn more about Kotlin Mutliplatform benefits.
With Kotlin Multiplatform, share the code using the mechanisms Kotlin provides:
Share code among all platforms used in your project. Use it for sharing the common business logic that applies to all platforms.
Share code among some platforms included in your project but not all. You can reuse much of the code in similar platforms using a hierarchical structure. You can use target shortcuts for common combinations of targets or create the hierarchical structure manually.
If you need to access platform-specific APIs from the shared code, use the Kotlin mechanism of expected and actual declarations.
Creating a multiplatform Kotlin library teaches how to create a multiplatform library available for JVM, JS, and Native and which can be used from any other common code (for example, shared with Android and iOS). It also shows how to write tests which will be executed on all platforms and use an efficient implementation provided by a specific platform.
Building a Full Stack Web App with Kotlin Multiplatform teaches the concepts behind building an application that targets Kotlin/JVM and Kotlin/JS by building a client-server application that makes use of shared code, serialization, and other multiplatform paradigms. It also provides a brief introduction to working with Ktor both as a server- and client-side framework.