Android Jetpack Compose vs XML: Why you Should Make the Switch 200OK Solutions Blog

Jetpack Compose vs XML is the biggest UI decision in Android development today. Jetpack Compose is a declarative UI toolkit that makes UI work simpler, while XML is the older view system many apps still use. This guide compares Jetpack Compose and XML, explains why Jetpack Compose is worth adopting, and covers the risks before you switch.

What does Jetpack Compose?

Jetpack Compose is a modern, fully declarative UI toolkit for building Android apps. Instead of describing screens in separate XML files, Jetpack Compose lets you build the UI in Kotlin, so logic and layout live together. Google released Jetpack Compose 1.0 as stable in 2021, so it is no longer new. Today, Jetpack Compose is the recommended way to build new Android UI.

Comparing Jetpack Compose and XML

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

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!"

With XML, the layout is only a static description. To change it, you find the view in Kotlin and update it yourself. This is the main difference in Compose vs XML: XML needs manual updates, while Jetpack Compose does not.

1.2 Code Conciseness

Jetpack Compose needs far less code. There are no separate layout files and no adapter classes for simple lists. A counter button takes a few lines:

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

XML needs layout files, styles and helper classes such as RecyclerView adapters. This makes an XML codebase longer and harder to change, while Jetpack Compose keeps the UI in one place.

1.3 State Management

Jetpack Compose has built-in state handling. When a state value changes, the composable that reads it recomposes. Jetpack Compose still works well with ViewModel and Flow, so you keep a clean architecture. With XML, you update views by hand or use data binding or observers to push state into them, which adds boilerplate.

1.4 Performance

Jetpack Compose updates only the parts of the UI whose state changed, which can keep screens efficient. XML can slow down with deeply nested layouts, and inflating layouts adds work. But there are trade-offs. Jetpack Compose performance depends on stable state, good code and Baseline Profiles, and debug builds feel slower than release builds. Measure your own app before you decide on Jetpack Compose vs XML performance.

1.5 UI Compositon

Jetpack Compose builds screens from small, reusable composables. You combine them like building blocks and pass data in as parameters. In XML, reuse means include tags, custom views or fragments, which are harder to nest and test. A LazyColumn in Jetpack Compose also replaces most RecyclerView work.

Why You Should Make the Switch to Jetpack Compose

Jetpack Compose is the direction Android UI is moving. Here are the practical reasons to switch.

2.1 Simplified Codebase

With Jetpack Compose you write UI in Kotlin and drop most XML layout files. The code is easier to read, refactor and review.

2.2 Better Integration with Kotlin

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

2.3 Reduced Boilerplate Code

No adapters, no view IDs, no findViewById. Jetpack Compose handles recomposition and state updates for you, so you write less glue code than in XML.

2.4 More Powerful UI Customization

Custom components in Jetpack Compose are plain functions. Animations, themes and layouts are easier to change than XML styles and custom views.

2.5 Improved UI Testing

You can test composables directly with createComposeRule and semantic matchers, without finding views by ID. Jetpack Compose testing is more direct than XML view tests.

Considerations Before Switching

Jetpack Compose has real benefits, but do not switch blindly.

Learning curve: Jetpack Compose is a different way of thinking. Teams used to XML need time to learn state, recomposition and side effects.

Migrating an existing app: You do not need to rewrite everything. Jetpack Compose works alongside XML. Use ComposeView to place Compose inside an XML screen, and AndroidView to use an old view inside Jetpack Compose. Start with new screens and move older ones later. This is the safest way to migrate from XML to Jetpack Compose.

Library support: Most popular libraries now support Jetpack Compose, but check custom views, older SDKs and map or ad libraries before you commit. XML is not deprecated, so a stable XML app does not have to move right now.

Looking to move your app from XML to Jetpack Compose? 200OK Solutions can help you plan the migration and build modern Android UI. Visit 200OK Solutions to explore our services.

Looking to modernize your Android app UI with Jetpack Compose? 200OK Solutions specializes in cutting-edge Android development. From XML to Jetpack Compose transitions, our experts ensure seamless, future-ready UI designs. Let us help you create stunning Android apps. Visit 200OK Solutions to explore our services today!

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