Compose Multiplatform
By JetBrains
Compose Multiplatform is JetBrains' cross-platform declarative UI framework that extends the programming model of Google's Jetpack Compose beyond Android to desktop, iOS, and web targets. It lets developers write a single Kotlin UI…
Definition
Compose Multiplatform is JetBrains' cross-platform declarative UI framework that extends the programming model of Google's Jetpack Compose beyond Android to desktop, iOS, and web targets. It lets developers write a single Kotlin UI codebase using composable functions and share it across platforms, rendering through a common graphics engine while still allowing platform-specific native code where it is genuinely needed, as part of the broader Kotlin Multiplatform ecosystem.
Overview
Compose Multiplatform grew out of JetBrains' broader Kotlin Multiplatform effort, which lets teams share business logic across Android, iOS, desktop, and web while keeping native UI on each platform. Compose Multiplatform extends that sharing further, into the UI layer itself, by taking the composable-function programming model that Google built for Jetpack Compose on Android and implementing rendering backends for other targets, so the same UI code can run natively on multiple platforms rather than only sharing logic underneath separate native interfaces. Mechanically, Compose Multiplatform reuses the same core APIs as Jetpack Compose — composable functions, `remember`-based state, the same layout primitives like `Column` and `Row` — but pairs them with platform-specific rendering. On desktop (Windows, macOS, Linux), it renders through Skia, the same graphics library Chrome and Android use, producing a native window with its own event loop. On iOS, it likewise renders via Skia into a native UIView, sitting alongside any existing UIKit or SwiftUI code. A web target compiles Kotlin to WebAssembly and renders similarly. Because rendering happens through a common graphics layer rather than mapping to each platform's native widget toolkit, visual output is consistent across platforms, at the cost of not using each OS's native controls by default. Compose Multiplatform sits within the Kotlin Multiplatform ecosystem alongside options like sharing only business logic with fully native UI per platform, or adopting more established cross-platform UI frameworks such as Flutter, which takes a similar single-codebase, custom-rendering approach but uses Dart instead of Kotlin. Compared to React Native, which bridges to native components, Compose Multiplatform and Flutter both render their own UI rather than wrapping platform widgets, trading native look-and-feel for rendering consistency and more predictable behavior across OS versions. In practice, teams adopt Compose Multiplatform to share UI code between an existing Jetpack Compose Android app and a new iOS or desktop version, to build cross-platform internal tools and utilities, or to maintain a single codebase for smaller apps where per-platform native UI investment isn't justified. JetBrains' own IDEs and tools have used it for parts of their interfaces, and the framework benefits from tight integration with Kotlin's coroutines and Compose's existing Android tooling. Limitations include a smaller ecosystem of third-party libraries compared to mature native frameworks, less access to certain OS-specific native UI conventions and accessibility behaviors without extra work, and dependence on JetBrains' rendering pipeline maturing for less common platform-specific interactions. Teams prioritizing maximum code sharing and consistent behavior across platforms benefit most; teams that need pixel-perfect native look-and-feel per platform often still choose fully native UI per platform instead.
Key Features
- Extends Jetpack Compose's programming model beyond Android
- Shares UI code across Android, iOS, desktop, and web targets
- Renders through Skia for consistent cross-platform visual output
- Built on Kotlin Multiplatform's shared business logic foundation
- Reuses familiar composable functions and state management APIs
- Coexists with native UIKit or SwiftUI code on iOS
- Supports desktop targets including Windows, macOS, and Linux
- Integrates with Kotlin coroutines for asynchronous UI logic
Use Cases
Alternatives
Frequently Asked Questions
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