From Kotlin Blog
Fri, October 16
Google Summer of Code 2026 With the Kotlin Foundation: Recap
Google Summer of Code 2026 has wrapped up! This was the Kotlin Foundation’s fourth year participating in GSoC, bringing new contributors into the Kotlin open-source ecosystem through hands-on projects and mentorship. This year, two projects successfully reached completion, tackling two areas of the ecosystem: improving recursion support in the Kotlin/Wasm backend and building a global […]
Thu, October 15
What Makes a Great KotlinConf Proposal?
The KotlinConf 2027 Call for Papers is now open! We invite developers from across the Kotlin community to bring their ideas, experiences, and expertise to the stage in Kraków. Do you have a Kotlin lesson or discovery that could help other developers? Perhaps you solved a difficult technical problem, introduced Kotlin into an existing codebase, […]
Wed, October 14
KotlinConf Recap: Lessons from Verifone’s Architect on Kotlin in Mission-Critical Payments
This article was written by an external contributor. Yuri Geronimus’s four-year-old son once asked him what his job was. Yuri told him he writes books: books that describe what he wants to change in the physical world. His son didn’t fully get it. Neither would most engineers: if you understand the words in your application […]
Wed, October 7
Start Your Next KMP App With Kotlin Toolchain 0.13
The Kotlin Toolchain is a unified entry point into Kotlin. It lets you build JVM, Android, iOS, multiplatform, and server-side applications with a simple declarative configuration. With the release of v0.13, we now recommend the Kotlin Toolchain for most new Kotlin Multiplatform (KMP) projects. Earlier this year, we promoted the Kotlin Toolchain to Alpha. Since […]
Mon, October 5
Discontinuing Swift Language IDE Support in the Kotlin Multiplatform Plugin
Starting with IntelliJ IDEA 2026.3 and Android Studio Rabbit 2 | 2026.2.2, we’re discontinuing Swift language IDE features in the Kotlin Multiplatform (KMP) plugin. This includes editing, syntax highlighting, and navigation within Swift files and between Swift and Kotlin. Running iOS applications and debugging Kotlin code on iOS will remain fully supported. Kotlin/Native functionality, such […]
Wed, September 30
The Companions to Come
We are working on extensions to our companions mechanism to unlock new code patterns and improve interoperability across different platforms. This post outlines these new features and provides preliminary guidance on migration. Companion blocks and extensions Many programming languages provide a notion of class or type members – functionality that does not belong to each […]
Tue, September 29
The State of Kotlin in 2026 Report
In 2026, Kotlin turned fifteen. Over those fifteen years, Kotlin has built a mature ecosystem, been adopted by companies around the world, and established a large and active developer community. Fifteen years is long enough to understand which technology trends lasted and which didn’t. This report looks back at Kotlin’s first fifteen years to see […]
Mon, September 28
A More Reliable Compilation Scheme for Kotlin Multiplatform Modules
The current compilation approach to Kotlin Multiplatform projects works, but sometimes can lead to unexpected or hard-to-predict behavior. For example: With Kotlin 2.5.0-Beta1, we introduced an optional “separate compilation” approach to KMP that solves both problems: make the compilation results consistent with IDE analysis, and point more consistently to problematic calls of library code from […]
Mon, September 7
Kotlin 2.4.20 Released
The Kotlin 2.4.20 release is out! Here are the main highlights: For the complete list of changes, see What’s new in Kotlin 2.4.20 or the release notes on GitHub. How to install Kotlin 2.4.20 The latest version of Kotlin is included in the latest versions of IntelliJ IDEA and Android Studio. To update to the […]
Thu, September 3
Kotlin Toolchain 0.12: Multiplatform Library Publishing, Wasm Apps, and More
Kotlin Toolchain 0.12.0 is out. This release brings some long-awaited features: multiplatform libraries publication, a preview of Wasm application support, Compose Hot Reload from the command line, and more. Read on for the details, and check the release notes for the full list of changes and bug fixes. Additionally, klibs.io now uses the Kotlin Toolchain […]
Wed, August 26
Compose Multiplatform 1.12.0 Released
Compose Multiplatform 1.12.0 is out! This version brings new tooling for AI assistants, improvements to web resource management, and finer control over desktop window states. Here are the highlights of this release: For a complete overview of the changes, check out What’s new in Compose Multiplatform 1.12.0 or the release notes on GitHub. Get Started […]
Thu, August 20
Signatures, be true: domain errors and functional handling in Kotlin
Here’s a function that signs a document: In Kotlin, Unit means the function completes without returning a meaningful value – roughly equivalent to void in Java. Got it? Now, tell me what could go wrong. You can’t. Yet, the code might be invalid. The signing window might have closed. The database might be down. The […]