When you’re done with this tutorial, your build.gradle file should look like this:

group 'io.javalin' // your group id
version '1.0-SNAPSHOT'

apply plugin: 'java'

sourceCompatibility = 11

repositories {

dependencies {
    implementation 'io.javalin:javalin:6.1.3'

Step by step instructions

  • File -> New -> Project
  • Select Gradle then Java (or Kotlin), click Next
  • Enter groupId and artifactId, click Next
  • Check Use auto-import, click Next

Open the newly generated build.gradle file and add the gradle-dependency
implementation 'io.javalin:javalin:6.1.3' to the dependencies {} scope. See the full build.gradle example above if you’re not sure where to put it.

Finally, create a file src/main/java/HelloWorld.java or src/main/kotlin/HelloWorld.kt
and paste the Hello World example:

  • Java
  • Kotlin
import io.javalin.Javalin;

public class HelloWorld {
    public static void main(String[] args) {
        var app = Javalin.create(/*config*/)
            .get("/", ctx -> ctx.result("Hello World"))
import io.javalin.Javalin

fun main() {
    val app = Javalin.create(/*config*/)
        .get("/") { ctx -> ctx.result("Hello World") }

Now everything is ready for you to start programming. Enjoy!