Android Jetpack Compose vs XML: Why you Should Make the Switch

Jetpack Compose vs XML is the biggest UI decision Android teams face today. Jetpack Compose is Google’s declarative UI toolkit, while XML is the View-based system that has powered Android screens for more than a decade. This guide compares the two across code volume, state, performance, composition and testing, explains why most teams are moving to Compose, and shows how to migrate an existing app without a risky rewrite.

What does Jetpack Compose?

Jetpack Compose is a modern, fully declarative UI toolkit for building native Android apps. Instead of describing screens in separate XML layout files and wiring them up in code, you describe the UI with Kotlin functions marked @Composable. Layout and logic live side by side, and when your data changes, Compose redraws only the parts of the screen that depend on it.

Google released Compose 1.0 as stable in July 2021, so it is no longer experimental. It is the recommended way to build new Android UI, and Google’s own samples, codelabs and documentation are now written for Android Compose first. Kotlin Jetpack Compose projects also get live previews in Android Studio, which shortens the feedback loop when you are tuning a layout.

Comparing Jetpack Compose and XML

Here is how Compose vs XML compares in the five areas that matter most to Android developers.

Area	XML Views	Jetpack Compose
UI model	Imperative: find the view, then change it	Declarative: describe the UI for the current state
Code volume	Layout files, styles, adapters, binding code	Kotlin functions, usually far less code
State	Manual updates, data binding or observers	Built-in, tracked by the framework
Reuse	Include tags, custom views, fragments	Small composable functions with parameters
UI testing	Find views by ID and Espresso matchers	Semantics-based test APIs

1.1 Declarative vs Imperative

Jetpack Compose (Declarative)

@Composable
fun GreetingList(names: List<String>) {
    Column {
        names.forEach { name ->
            Text("Hello, $name!")
        }
    }
}

In this Jetpack Compose example, GreetingList recomposes automatically when the names list changes. You describe what the UI should look like, and Jetpack Compose updates it.

XML (Imperative)

<TextView
    android:id="@+id/hello_text"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"/>

val text = findViewById<TextView>(R.id.hello_text)
text.text = "Hello, $name!"

The XML file only describes the starting layout. To change anything, you look up the view in Kotlin and update it by hand, and every missed update becomes a potential bug. That manual step is the main difference in XML vs Jetpack Compose.

1.2 Code Conciseness

Compose needs far less code for common screens. There are no separate layout files, no view IDs and no adapter classes for simple lists. A counter button takes a handful of lines:

@Composable
fun Counter() {
    var count by remember { mutableStateOf(0) }
    Button(onClick = { count++ }) {
        Text("Count: $count")
    }
}

The XML version needs a layout file, an ID, a click listener and a line that updates the text. Multiply that across dozens of screens, along with styles and RecyclerView adapters, and an XML codebase becomes longer and harder to change. Compose keeps the UI in one place.

1.3 State Management

State handling is built into Compose. When a state value changes, every composable that reads it recomposes. You also keep a clean architecture, because Compose works well with ViewModel and Kotlin Flow:

@Composable
fun ProfileScreen(viewModel: ProfileViewModel = viewModel()) {
    val state by viewModel.uiState.collectAsStateWithLifecycle()
    ProfileContent(state = state)
}

With XML, you either update views manually or use data binding and observers to push state into them. Both approaches work, but they add boilerplate and one more place for the UI and the data to drift apart.

1.4 Performance

Compose updates only the parts of the UI whose state changed, which keeps most screens efficient. XML can slow down with deeply nested layouts, and inflating those layouts adds work on every screen.

There are trade-offs, though. Compose performance depends on stable state, sensible code and Baseline Profiles. Debug builds also feel noticeably slower than release builds, which surprises many teams during their first evaluation. Always test a release build, ideally with a Baseline Profile, and measure your own app before you settle the Jetpack Compose vs XML performance question.

1.5 UI Compositon

Compose builds screens from small, reusable composables. You combine them like building blocks and pass data in as parameters, which makes a design system far easier to maintain. In XML, reuse means include tags, custom views or fragments, all of which are harder to nest and test. A LazyColumn in Jetpack Compose also replaces most RecyclerView work: no adapter, no ViewHolder, just a list of items and a composable for each one.

Why You Should Make the Switch to Jetpack Compose

Compose is the direction Android UI is moving, and the practical benefits show up quickly in day-to-day work.

2.1 Simplified Codebase

With Jetpack Compose you write UI in Kotlin and drop most XML layout files. The result is code that is easier to read, refactor and review, because the layout and the logic that drives it sit in the same place.

2.2 Better Integration with Kotlin

Compose uses Kotlin features such as lambdas, type safety and coroutines. Your UI code and business code share one language, which lowers context switching and helps teams move faster.

2.3 Reduced Boilerplate Code

There are no adapters, no view IDs and no findViewById. Compose handles recomposition and state updates for you, so you write less glue code than you would with XML.

2.4 More Powerful UI Customization

Custom components in Compose are plain functions. Animations, themes and layouts are easier to change than XML styles and custom views, and a Jetpack Compose example for a custom card or a animated button is often a few lines long.

2.5 Improved UI Testing

You can test composables directly with createComposeRule and semantics-based matchers, without hunting for views by ID:

@get:Rule
val composeTestRule = createComposeRule()

@Test
fun counter_increments() {
    composeTestRule.setContent { Counter() }

    composeTestRule.onNodeWithText("Count: 0").performClick()
    composeTestRule.onNodeWithText("Count: 1").assertIsDisplayed()
}

Compose tests are more direct than XML view tests, and they run well alongside your existing Espresso suite.

Considerations Before Switching

Compose has real benefits, but do not switch blindly. These are the points worth checking first.

Learning curve. Compose is a different way of thinking. Teams used to XML need time to learn state, recomposition and side effects such as LaunchedEffect. Budget for it, and start with a small screen. The official codelabs and any good Jetpack Compose tutorial will get a team productive within a few weeks.

Migrating an existing app. You do not need to rewrite everything. Compose works alongside XML, so you can migrate from XML to Jetpack Compose one screen at a time. Use ComposeView to place Compose inside an XML screen, and AndroidView to use an old view inside Compose:

// Compose inside an XML screen
findViewById<ComposeView>(R.id.compose_view).setContent {
    Counter()
}

// A legacy view inside Compose
AndroidView(factory = { context -> WebView(context) })

This interoperability is what makes migration safe. Start with new screens, move simple old screens next, and leave complex ones for last. If you host Compose in a Fragment, set an appropriate ViewCompositionStrategy so compositions are disposed correctly.

Library support. Most popular libraries now support Compose, including image loading, navigation and maps. Before you commit, check custom views, older SDKs and any ad or map libraries your app depends on. XML is not deprecated, so a stable XML app does not have to move right now.

Tooling. Use a recent version of Android Studio for Jetpack Compose, so you get previews, layout inspection and the latest lint checks.

The bottom line. For new screens and new apps, Android Jetpack Compose is the better default. For existing apps, an incremental move from XML to Jetpack Compose gives you the benefits without the risk of a full rewrite.

Planning to move your app from XML to Jetpack Compose? 200OK Solutions helps teams plan the migration, modernize Android UI and ship cleaner, future-ready apps. Talk to 200OK Solutions to discuss your project.