Compose Multiplatform

You write one Compose UI tree in commonMain and let each platform be a thin host. The whole discipline is one sentence: common by default, platform by exception. Every line you put in commonMain ships to Android, iOS, and desktop unchanged; every line you put in a platform source set is a deliberate exception you should be able to justify.

Versions floor (2026)

Pin these or the K2 compiler bites you. Verify against current docs before locking a project — these are the floors, not opinions.

• Compose Multiplatform 1.11.0, bundling Jetpack Compose 1.11.1.
• Kotlin 2.1.0+ required (2.2.20 recommended for evolving iOS/Web targets). Since CMP 1.8.0 the K2 compiler is mandatory, so every dependency must compile against Kotlin 2.1.0+.
• iOS is Stable (production-ready since CMP 1.8.0, May 2025): feature parity for popular cases, type-safe navigation with deep linking, accessibility (VoiceOver, Full Keyboard Access).
• Web is Beta (CMP 1.9.0, Sept 2025), runs on WasmGC browsers. Do not promise Web parity — ship Android/iOS/desktop, pilot Web.
• Platform minimums: Android API 21, iOS 14+, macOS 13 arm64, Windows 10+, Ubuntu 20.04+, desktop JDK 11+ (17+ for jpackage packaging).

Where does this code go?

This is the question you answer dozens of times a day. Default to the leftmost column that compiles.