A real alternative to Flutter
Sound familiar?
You already have a solid Android app written in Kotlin. Rebuilding it in Flutter to get iOS feels like throwing good work away, but maintaining two separate apps is doubling every feature.
For years, "cross-platform" mostly meant Flutter or React Native. Kotlin Multiplatform (KMP) changed that. Compose Multiplatform, JetBrains' shared UI toolkit, reached stable on iOS with version 1.8.0 in May 2025. Version 1.11 in May 2026 added an experimental native text input on iOS and turned on concurrent rendering by default. Google's Android documentation now covers Kotlin Multiplatform directly.
The core difference
Kotlin Multiplatform
- Share business logic, networking and data; keep native screens if you want
- Optionally share UI too, with Compose Multiplatform
- Adopt one feature at a time inside existing apps
- Written in Kotlin, the standard language for Android
Flutter
- Share everything: logic and UI in one codebase
- Its own renderer draws an identical interface everywhere
- Usually a new app, or embedded screen by screen
- Written in Dart
Side by side
| Kotlin Multiplatform (+ Compose) | Flutter | |
|---|---|---|
| Maker | JetBrains, with Google support on Android | |
| Latest release | Compose Multiplatform 1.11 (May 2026) | Flutter 3.47 (August 2026) |
| Android, iOS, desktop | Stable | Supported |
| Web | Beta (Kotlin/Wasm); stable via Kotlin/JS for logic | Supported; WebAssembly planned as default |
| UI approach | Native UI per platform, or shared Compose UI | Shared Flutter UI |
| Adding to an existing app | Incremental, one module at a time | Possible, but brings its own UI layer |
| Best fit team | Kotlin and Android developers | One team building a new app |
Sources: Kotlin Multiplatform platform stability, Compose Multiplatform 1.11, Compose Multiplatform 1.8.0, Flutter 3.47.
How to choose
IfYou have a working native Android app in Kotlin
ThenKotlin Multiplatform: share its logic with iOS without a rewrite.
IfYou want iOS screens to stay fully native in SwiftUI
ThenKotlin Multiplatform for logic only, with native UI on each platform.
IfYou are starting from scratch with one small team
ThenFlutter is usually faster to a first release on both platforms.
IfYou need a custom, identical design everywhere, including the web
ThenFlutter, whose web support is more mature today.
IfYour team knows React and TypeScript
ThenCompare React Native too. See Flutter vs React Native.
Want to see what your apps could share?
Get a free consultationThe practical path
The lowest-risk way to try Kotlin Multiplatform is to share one well-defined piece first, such as the API client or validation rules, and measure how much duplicated work disappears. If it works, share more. Flutter decisions are bigger up front, because the UI moves with the code.
For desktop and web targets, see one app for mobile and desktop. For help building, see our mobile app development services, Kotlin and Flutter work.
Key takeaway
Kotlin Multiplatform shares logic and lets you keep native screens; Flutter shares everything. Existing Kotlin apps favour KMP; new apps built by one team often favour Flutter.
Frequently Asked Questions
Written by
Vishvas Patel
Mobile & Desktop Engineering
