Sharing UI with Compose Multiplatform

From shared logic to shared UI

So far we’ve shared everything below the UI. Compose Multiplatform (by JetBrains, built on Jetpack Compose) takes it further: you can write your screens once in Compose and run them on Android, iOS, desktop and web.

A shared screen

@Composable
fun App() {
    var count by remember { mutableStateOf(0) }
    MaterialTheme {
        Column(
            modifier = Modifier.fillMaxSize().padding(16.dp),
            horizontalAlignment = Alignment.CenterHorizontally
        ) {
            Text("Clicks: $count")
            Button(onClick = { count++ }) { Text("Tap me") }
        }
    }
}

This exact composable renders on every platform — the same UI, drawn by Compose’s engine, not translated to native widgets.

How each platform shows it

• Android — call App() inside setContent { } as usual.
• iOS — Compose Multiplatform provides a UIViewController wrapper you embed in your SwiftUI/UIKit app.
• Desktop / Web — small entry points host the same App().

When to share UI vs go native

• Share UI (Compose Multiplatform) — great for internal tools, content apps, MVPs, and small teams who want maximum reuse and speed.
• Native UI (SwiftUI on iOS) — better when you need the exact platform feel, the newest OS UI features, or deep platform integration. Common for consumer apps where iOS users expect a true iOS look.

You can even mix: share most screens but build a few critical ones natively.

Maturity

Compose Multiplatform is stable for Android, desktop and iOS, with web steadily maturing. iOS support is production-ready and improving rapidly — many teams ship with it today.

The spectrum of sharing

It helps to see KMP as a dial, not a switch:

1. Share models + networking only (most conservative).
2. Add repositories + business logic.
3. Add ViewModels / presentation.
4. Add UI with Compose Multiplatform (most aggressive).

Pick the point on the dial that fits your team and product.

Common mistakes

• Sharing the UI before the logic layer is solid — share logic first.
• Forcing shared UI on iOS when users expect a fully native feel.
• Treating it as all-or-nothing instead of choosing a level of sharing.

Summary: Compose Multiplatform lets you share whole screens across platforms, not just logic. Think of KMP as a dial — share models, then logic, then ViewModels, then optionally UI — and choose native UI on iOS when the platform feel matters most.