Is Kotlin free to use?

Yes. Kotlin is open-source and free. The compiler and standard library are released under the Apache 2.0 license.

Do I need to know Java to learn Kotlin?

No. You can learn Kotlin from scratch without any Java knowledge. However, if you already know Java, switching to Kotlin will feel natural and fast.

Can Kotlin replace Java completely?

In many projects, yes. Kotlin is fully interoperable with Java, so you can gradually migrate existing Java code. For Android and many backend projects, Kotlin is now the primary language.

Beginner 5 min readKotlin 2.0

What is Kotlin? A Beginner-Friendly Introduction

Kotlin is a modern, statically typed programming language that runs on the JVM. Learn what makes it special and why so many developers are switching to it.

What You Will Learn

What Kotlin is and where it runs
Why Kotlin was created and by whom
What Kotlin is used for today
How Kotlin compares to Java at a glance
Your first Kotlin program

What is Kotlin?

Kotlin is a modern programming language created by JetBrains, the company behind IntelliJ IDEA. It first appeared in 2011 and reached its stable 1.0 release in 2016. Today it is one of the most popular languages for Android development and is growing fast in backend and multiplatform projects. Kotlin is statically typed, which means the type of every variable is known at compile time. This helps catch bugs early without making the code overly verbose.

Your First Kotlin Program

kotlin
fun main() {
    println("Hello, Kotlin")
}

Output

Hello, Kotlin

Every Kotlin program starts with a main function. println() prints text followed by a newline. This is the simplest complete Kotlin program you can write.

Beginner Tip: You do not need a class to write a Kotlin program. Unlike Java, Kotlin functions can live at the top level of a file.

Kotlin is 100% interoperable with Java. You can call Java libraries from Kotlin and Kotlin code from Java.

Where Does Kotlin Run?

Kotlin compiles to several targets: - **Kotlin/JVM** — runs on the Java Virtual Machine, works anywhere Java runs - **Kotlin/JS** — compiles to JavaScript for web development - **Kotlin/Native** — compiles to native binaries (iOS, macOS, Linux, Windows) - **Kotlin/Wasm** — experimental WebAssembly target This flexibility is what makes Kotlin Multiplatform possible: you write shared business logic once and deploy it everywhere.

Best Practice: Start with Kotlin/JVM. It has the most tooling support, the largest library ecosystem, and the smoothest learning path for beginners.

What is Kotlin Used For?

Kotlin has a wide range of real-world applications: 1. **Android development** — Since 2017, Google has recommended Kotlin as the preferred language for Android 2. **Backend development** — Frameworks like Ktor and Spring Boot have first-class Kotlin support 3. **Multiplatform apps** — Share code across Android, iOS, web, and desktop 4. **Desktop applications** — Using Compose Multiplatform 5. **Scripting** — Kotlin can be used as a scripting language with .kts files

💡 Real-world use case: Companies like Google, Netflix, Pinterest, Uber, and Atlassian use Kotlin in production.

Practice Exercise

Exercisemultiple choice

Who created the Kotlin programming language?

Quick Quiz

Which of these is NOT a compilation target for Kotlin?

What is Kotlin? A Beginner-Friendly Introduction

What You Will Learn

What is Kotlin?

Your First Kotlin Program

Where Does Kotlin Run?

What is Kotlin Used For?

Practice Exercise

Quick Quiz

Frequently Asked Questions

Related Tutorials