I've been watching KMP since its early days. I've shipped KMP code in production. My honest assessment: 2025 is the year it crossed the threshold from "promising but risky" to "production-ready for most teams."
Here's what changed, what still hurts, and when to pick it over Flutter.
What Kotlin Multiplatform actually is in 2025
KMP (Kotlin Multiplatform) lets you share Kotlin code across Android, iOS, Web (via Kotlin/Wasm and Kotlin/JS), and Desktop (JVM). With Compose Multiplatform, you can now share UI code too — not just business logic.
The big milestones that changed things
- KMP Stable (November 2023) — JetBrains declared the core production-ready
- Compose Multiplatform 1.6 (2024) — iOS target went stable
- Fleet IDE — better multiplatform development experience
- Kotlin 2.0 — improved compiler performance and K2 type system
Where it shines
KMP is exceptional for teams with existing Kotlin expertise who need to share business logic without the overhead of a React Native or Flutter bridge. You get:
- Genuinely native performance (no bridge)
- Full access to platform APIs
- Familiar Kotlin coroutines and Flow
- Strong type system across shared and platform code
The rough edges (being honest)
KMP isn't perfect. The honest list of challenges in 2025:
- iOS debugging is still harder than Android debugging
- Library ecosystem — not everything has KMP support. Ktor, SQLDelight, and Koin work well. Many others don't
- Compose on iOS — performance is good but not identical to SwiftUI for complex animations
- Team learning curve — iOS developers unfamiliar with Kotlin need ramp-up time
KMP vs Flutter — the honest comparison
| Consideration | KMP | Flutter |
|---|---|---|
| Existing Android team | ✅ Natural fit | ⚠️ Need Dart skills |
| UI consistency across platforms | ⚠️ Good, not pixel-perfect | ✅ Identical on all platforms |
| Platform-specific features | ✅ Full native access | ⚠️ Plugin required |
| Performance | ✅ Native | ✅ Near-native |
| Hiring pool | ⚠️ Smaller | ✅ Large and growing |
| AI app development | ✅ Great with Gemini SDK | ✅ Great with google_generative_ai |
My recommendation
Pick KMP if you have an Android-first team with strong Kotlin skills, need deep platform integration on both platforms, and are building something where the native feel on iOS matters significantly.
Pick Flutter if you're starting fresh, want the widest possible talent pool, need Web + Mobile in the same codebase, or are building a consumer app where UI consistency across platforms is a feature.
Both are excellent choices in 2025. The team's existing expertise matters more than the framework's technical capabilities.