Kotlin

Concise. Multiplatform. Fun.

Get started

Developed by

Kotlin for Backend

Spring support, Java interop, coroutines.

Try Now

Kotlin for Server

Spring support, Java interop, coroutines.

Try Now

Kotlin for Backend

A simple way to boost your coding joy.

Try Now

Kotlin for Server

A simple way to boost your coding joy.

Try Now

Kotlin for Backend

A simple way to boost your productivity.

Try Now

Kotlin for Server

A simple way to boost your productivity.

Try Now

Latest news

January 16, 2026

Update your Kotlin projects for Android Gradle Plugin 9.0

Android Gradle plugin 9.0 is now available, and it includes two major changes that will affect existing Kotlin projects: This post provides some details about these changes and points you to the resources that you’ll need to update your existing projects. You’ll also need to update tools and plugins that depend on AGP to their […]

January 13, 2026

Compose Multiplatform 1.10.0: Unified @Preview, Navigation 3, and Stable Compose Hot Reload

Compose Multiplatform 1.10.0 has been released! We’re continually developing our multiplatform APIs and expanding support for Jetpack libraries commonly used on Android. Here are the highlights of this release: Get Started with Compose Multiplatform For a complete overview of the changes, check out What’s new in Compose Multiplatform 1.10.0 or the release notes on GitHub. […]

January 13, 2026

The Journey to Compose Hot Reload 1.0.0

Compose Hot Reload has just been promoted to stable with our 1.0.0 release. We worked hard to build a technology that is easy to use and well-integrated into existing tools while also requiring zero configuration from users. The tool is bundled with Compose Multiplatform, starting from version 1.10 (see our dedicated release blog post). While […]

January 13, 2026

Building AI Agents in Kotlin – Part 4: Delegation and Sub-Agents

Previously in this series: In the previous installment, we saw how to set up tracing, which brings us to two new questions: What should we experiment with based on the information this tool provides? And what parts of our agent could we improve using its observations? The first idea we had was to experiment with […]

Kotlin blog

Why Kotlin?

fun main() {
    val name = "stranger"        // Declare your first variable
    println("Hi, $name!")        // ...and use it!
    print("Current count:")
    for (i in 0..10) {           // Loop over a range from 0 to 10
        print(" $i")
    }
}

Get started

Kotlin in action

McDonald's leverages Kotlin Multiplatform (KMP) for their global mobile app, enabling them to build a codebase that can be shared across platforms, removing the need for codebase redundancies.Kotlin Multiplatform

AWS opted for Kotlin over Java for Amazon Quantum Ledger Database (QLDB) thanks to its expressiveness and structured concurrency. They rewrote QLDB in Kotlin, enhancing the user experience, benefiting from its development workflow, and adopting it fully for server-side development.Server-side

Philips utilizes Kotlin Multiplatform in its HealthSuite digital platform mobile SDK. With KMP, they accelerated the implementation of new features and fostered increased collaboration between Android and iOS developers.Kotlin Multiplatform

Adobe Experience Platform chose Kotlin for server-side development because of its concise syntax, async capabilities, and interoperability with Java. This shift boosted productivity and improved the developer experience, replacing Java for real-time services.Server-side

By sharing over 80% of logic across iOS and Android, Forbes now rolls out new features simultaneously on both platforms, keeping the flexibility to withhold or customize features based on the specific platform.Kotlin Multiplatform

Atlassian adopted Kotlin for the Jira Software cloud, leveraging its Java compatibility for seamless integration and minimizing migration challenges. Kotlin's ease of use improved developer productivity and boosted team satisfaction and efficiency.Server-side

See all case studies

Share code on your terms and for different platforms

Simplify the development of cross-platform projects with Kotlin Multiplatform. It reduces time spent writing and maintaining the same code for different platforms while retaining the flexibility and benefits of native programming. Kotlin applications will work on different operating systems, such as iOS, Android, macOS, Windows, Linux, watchOS, and others.

Learn about Kotlin Multiplatform

Kotlin + AI

JetBrains is investing in AI models tailored for Kotlin, providing open data, benchmarks, and AI-native tooling integrated into your workflow.

At the same time, Kotlin makes it easy to build your own AI-powered features with seamless backend integrations and a growing ecosystem.

What you get with Kotlin + AI

Strong support across JetBrains AI tools like AI Assistant and Junie
Robust functionality for building AI-powered apps on the JVM
Native integration with tools like Spring AI and LangChain4j
Open data and benchmarks for better code generation

Learn about JetBrains AI Build AI apps with Kotlin

Build your own AI agents with Koog

Koog is JetBrains’ new Kotlin-native framework for creating powerful AI agents that run locally, interact with tools, and automate complex tasks. Whether you’re developing a simple chat assistant or an advanced multi-step workflow, Koog gives you full control with clean Kotlin code – no external services are required. Build, extend, and experiment with AI agents entirely in Kotlin.

Get started

Big, friendly and helpful community

Kotlin has great support and many contributors in its fast-growing global community. Enjoy the benefits of a rich ecosystem with a wide range of community libraries. Help is never far away — consult extensive community resources or ask the Kotlin team directly.

Kotlin Foundation

Actively supports community efforts in developing the Kotlin ecosystem.

Learn more

Start using Kotlin today!

Get started