Get started with Kotlin/Wasm and Compose Multiplatform

This tutorial demonstrates how to run a Compose Multiplatform app with Kotlin/Wasm in IntelliJ IDEA and generate artifacts you can publish as a website.

Create a project

Set up your environment for Kotlin Multiplatform development.
In IntelliJ IDEA, select File | New | Project.
In the list of project templates, select Kotlin Multiplatform.
If you're not using the Kotlin Multiplatform IDE plugin, you can generate the same project using the KMP web wizard.
Specify the following fields in the New Project window:
- Name: WasmDemo
- Project ID: wasm.project.demo
This tutorial uses wasm.project.demo as the Project ID for consistency. However, we recommend keeping your usual group ID, such as org.example. Whatever you enter here will be suggested as the default in future projects.
Select the Web target and the Share UI tab. Make sure that no other options are selected.
Click Create.

Run the application

Once the project loads, select webApp [wasmJs] in the list of run configurations and click Run.
The web application opens automatically in your browser. Alternatively, once the build finishes, you can open the following URL manually:
http://localhost:8080/
The port number may vary if port 8080 is already in use. You can find the actual port number in the output of the Gradle build.
Click the Click me! button. This reveals the Compose Multiplatform logo:

Generate artifacts

Generate your project's artifacts to publish on a website:

Open the Gradle tool window by selecting View | Tool Windows | Gradle.
In WasmDemo | Tasks | kotlin browser, select and run the wasmJsBrowserDistribution task.
You need at least Java 11 as your Gradle JVM for the tasks to load successfully. For Compose Multiplatform projects in general, we recommend Java 17 or later.
Alternatively, you can run the following command in the terminal from the WasmDemo root directory:
./gradlew wasmJsBrowserDistribution

Once the task completes, you can find the generated artifacts in the webApp/build/dist/wasmJs/productionExecutable directory:

Publish the application

Use the generated artifacts to deploy your Kotlin/Wasm application. Select a publishing option that you prefer and follow the instructions:

Once your site is created, open the browser and navigate to your platform's page domain. For example, GitHub pages:

Congratulations! You have published your artifacts.

What's next?

Learn how to share UIs between iOS and Android using Compose Multiplatform
Try more Kotlin/Wasm examples:
Join the Kotlin/Wasm community in Kotlin Slack:

18 May 2026