📣 Kotlin 2.4.0 is out! Here are some of the highlights: • Language: Stable context parameters, explicit backing fields, and multiple features for annotation use-site targets. • Standard library: Stabilized support for the UUID API and support for checking sorted order. • Kotlin/JVM: Support for Java 26 and annotations in metadata enabled by default. • Kotlin/Native: Support for Swift packages as dependencies, updates on Swift export, and the CMS GC enabled by default. • Kotlin/Wasm: Incremental compilation enabled by default and support for WebAssembly Component Model. • Kotlin/JS: Support for value class export and ES2015 features in JS code inlining. • Gradle: Compatibility with Gradle 9.5.0. • Maven: Automatic alignment between Java and JVM target versions. • Kotlin compiler: More consistent inline function behavior during

.klib

compilation. Learn more👇

🎮 Kodee vs. Friction is here! To celebrate 15 years of Kotlin, we’re launching a browser arcade game built with Kotlin and Compose Multiplatform for web. For the best experience, we recommend playing on a desktop or laptop. Fight bugs and unlock Kotlin power-ups inspired by null safety, the Elvis operator, coroutines, smart casts, Kotlin Multiplatform, and more. Face enemies like Legacy Slime, Boilerplate Golem, Callback Hydra, and the Final Void. Play the game, survive the chaos, and climb the leaderboard kodee happy https://kotl.in/wm1kb3

Adopting Kotlin Multiplatform was a calculated bet for Booking.com – and the results exceeded expectations kodee greetings Discover how KMP improved cross-platform consistency and proved to be a viable long-term solution for the team. Read the full story 👇

The 2026 Kotlin Foundation Grant Program for library authors is now open! Developers maintaining open-source Kotlin Multiplatform projects, including libraries, tools, and frameworks, can now apply for a new round of financial support. 👇

🎉 Kotlin turns 15 this year! 🎉 To mark this special occasion, we've brought

the Kotlin Effect▾

into real life – making everyday situations more concise, efficient, and fun. Join us in celebrating 15 years of Kotlin and its impact on developers, teams, and the community! Explore the Kotlin Effect further: https://kotl.in/36tfbq

🎉 Kotlin is turning 15 – and now is a great time to take your Kotlin skills further. To celebrate, we’re offering free access to select Kotlin courses on Hyperskill, so you can deepen your Kotlin knowledge with hands-on, project-based learning. Build real projects, explore more advanced Kotlin topics, and continue developing your skills for mobile, backend, web, and desktop development. 👉 Explore the Kotlin courses

Amper 0.11.0 is out, and with it comes a major update: 📣 Amper is officially evolving into the Kotlin Toolchain! 📣 Everything you know from Amper now lives under a single kotlin command as a unified entry point into the ecosystem. What's new in v0.11: • Publishing preview: A first look at built-in publishing, with everything you need to satisfy Maven Central requirements in just a few lines of configuration. • Plugin developer APIs: New custom check/command blocks and improved diagnostics. • TUI and IDE improvements: Faster background source downloads and upgraded terminal progress indicators. Read the full update

Explore the Kotlin Effect kodee happy Watch our anniversary video, play the Kodee vs. Friction browser game, and level up your Kotlin skills with hands-on learning resources. See how Kotlin empowers developers and teams building for mobile, backend, web, and desktop.

K Last chance to share your feedback! The Kotlin Release Survey is wrapping up – tell us what’s working, what’s missing, and what you’d love to see next. ➡️ https://surveys.jetbrains.com/s3/Kotlin-release-3

📢 Kotlin Notebook is transitioning to a community-driven, open-source project on GitHub (Apache 2.0). Starting with v2026.2, it's no longer bundled with IntelliJ IDEA (though it will still be available from the Marketplace). JetBrains will no longer officially maintain or support the plugin, but development will continue in the open with community contributions. Any future JetBrains involvement will be on a best-effort basis. For Kotlin data analysis users: Kotlin DataFrame is unaffected and continues to evolve independently. Recent releases make it much easier to bring notebook-style, type-safe data transformations into regular Kotlin projects. The DataFrame compiler plugin brings schema-aware APIs and generated column accessors into Gradle and Maven projects, usable in ordinary

.kt

files. The latest release is 1.0.0-Beta5. alphabet white questionQuestions about migrating workflows? The #C4W52CFEZ channel is the place. Full details in the blog post.

Kotlin support is now available in BlueJ 6.0! 💙 Developed in collaboration with the Programming Education Tools group at King’s College London, Kotlin support brings a modern JVM language into one of the most established environments for teaching introductory object-oriented programming. With Kotlin in BlueJ, students can keep the familiar objects-first workflow – visual class diagrams, the object bench, and direct object interaction – while writing clearer, more concise code. Download BlueJ 6.0 and get started with Kotlin in BlueJ

🤖 Want to try building a Kotlin application with Claude Agent? Follow this hands-on tutorial to create a task manager app with Kotlin and Spring Boot directly in IntelliJ IDEA. You’ll learn how to use Claude Agent to plan the application, implement the features, review the generated changes, run tests, and refine the UI step by step. Start building👇

📣 There's still time to apply for the Kotlin Foundation Grants for Library Authors. Applications close on July 14, 2026.

🛠️ Switch your Kotlin Multiplatform project from CocoaPods to SwiftPM dependencies with Junie. Working with a KMP module that relies on CocoaPods dependencies and planning to try the experimental SwiftPM import integration? This step-by-step guide shows how to use Junie and a Kotlin AI skill to assist the migration process. You’ll learn how to: ➡️ Set up Junie CLI and install the migration skill ➡️ Start the migration in your project ➡️ Review the generated changes in Git ➡️ Test the migrated project Read the guide👇

set the channel topic: Welcome to K Slack. The topic is Kotlin. Be Kind. Be Considerate. CoC and guidelines https://kotlinlang.org/docs/slack-code-of-conduct.html#slack-code-of-conduct.md

K*Introducing the Kotlin Benchmark* An open, reproducible benchmark for evaluating AI coding agents on Kotlin software engineering tasks. It uses 105 issues from active open-source Kotlin repositories, validated by each project’s own test suite. Beyond resolution scores, the leaderboard reports average token consumption and latency, so you can weigh each setup on cost and speed, not just correctness. This is our first iteration. Newer models are already being evaluated, with updated results coming soon. See the leaderboard and learn more ⬇️

📣 Library grant program – last call! There's still time to apply for a Kotlin Foundation grant for Multiplatform library authors. Applications are open 📆 until July 14, 23:59 CEST. Learn more and apply here 👇

📢 Kotlin 2.4.10 is here! This release brings performance improvements and bug fixes. Changelog: ➡️ kotl.in/x74s6p

Join the Kotlin birthday party by creating your own postcard! Leave a birthday wish or bold prediction for Kotlin's future. You can also upload your photo and celebrate alongside Kodee. Once you've created your postcard, drop it in this thread. Let's fill the channel with birthday wishes for Kotlin's future! 💜 kotl.in/wj8xba

kodee electrified Kodee is more than Kotlin’s mascot. What began as an idea for bringing more warmth and personality to the programming language evolved into a vibrant character shaped by research, creative iteration, and feedback from the Kotlin community. With an expressive design, tech-savvy charm, and playful spirit, Kodee has become a symbol of Kotlin’s inclusive and developer-friendly culture. Discover the story behind Kodee’s journey from concept to community icon👇

K*Help us understand where AI falls short with Kotlin – and get rewarded!* At Kotlin, we’re working to build an ecosystem that better supports AI-powered workflows. We are looking to collect detailed examples of where and how AI tools struggle with Kotlin, and we would love your help. See here for how to get involved. We look forward to your responses and to building a stronger Kotlin ecosystem together 💪

🚀 Already know Kotlin? Reuse your skills to build for Android, iOS, desktop, and web. RevenueCat Shipaton 2026 is your chance to turn your next app idea into a real product with Kotlin Multiplatform and Compose Multiplatform. Build and launch your app between August 1 and September 30 and compete for the Ship Kotlin Everywhere Award. Share your journey with others to earn extra points. Learn more and register 👇 kotl.in/ei3top

Please share your feedback 👇

👋 Using Compose Multiplatform and want more people to know about your app? We’re refreshing the Compose Multiplatform app showcase, and we’re after the beautiful stuff: apps where the UI makes people ask what it’s built with. It’s a good fit if your app: • is live in production or public beta; • uses Compose Multiplatform for at least part of the UI; • is available on the App Store or Google Play; • looks good enough that you’d screenshot it yourself 🤘🏻. Selected apps may be featured on Kotlin and JetBrains websites, social media, in talks and other materials, with a link so people can try them. You don’t have to be a household name yet: established products and fast-growing apps are both interesting to us, from company products to indie projects and open source. Submit here: surveys.jetbrains.com/s3/Compose-Mult…

Hey everyone! A month ago we shared that Shipaton 2026 is on, and since then the KMP category has been filling up with builds. If you missed it or filed it under “later”, here’s your reminder: there are still six weeks left, and that’s genuinely enough. Proof: last year Rehaan entered with zero KMP experience, learned it during the build window, shipped his app Posturely to the stores in time, and took 2nd place in our category. In his words:

“Shipaton showed me how quickly you can learn and build with Kotlin Multiplatform, especially when using AI as a learning partner. Finishing my first KMP project in time, and then placing second, was an incredible surprise.”

The short version of what’s at stake: build and ship a mobile app with KMP by Sep 30, compete for the Ship Kotlin Everywhere Award, $30,000 across three winners, top app goes on a Times Square billboard. Starter Guide, AI Guide, IntelliJ IDEA Ultimate and Junie access included. And this Tuesday (Aug 25, 9am PT / 6pm CEST) we’re going live with RevenueCat: a KMP talk by @zsmb, category-winning tips from @Pamela Hill Hill-Galloway (she judged it last year), and open Q&A. Great place to start if you’re on the fence 👉 All the details and registration: kotlinlang.org/lp/shipaton

📢 Kotlin 2.4.20 is out! Here are some of the highlights: ✅ Standard library: Support for coroutine stack trace recovery, new functions for checking the equality and uniqueness of collection elements, and new overloads for kotlin.test assertion functions ✅ Kotlin/Native: New Swift export features, improved incremental compilation, and automatically generated Package.swift files for SwiftPM dependencies ✅ Kotlin/Wasm: Changes to top-level

require()

calls in

@JsFun

declarations, improved initialization order of companion objects, support for Wasmtime in the Kotlin Gradle plugin, new compilation modes, and reduced binary size for functional interfaces ✅ Kotlin/JS: A new DSL for browser testing, support for exporting suspending lambdas as async functions, improved exportability of data classes ✅ Gradle: Support for Gradle 9.7.0 and improved reporting in the Problems API ✅ Build tools API: Support for new targets: Kotlin/JS, Kotlin/Wasm, and Kotlin metadata ✅ Kotlin compiler: kotlinr runner command and a separate native image

Kotlin Toolchain 0.12 is out! kodee happy What's new: • Multiplatform library publishing across all Kotlin platforms (previously JVM-only) • Preview of Wasm app support: Run with

kotlin run

• Compose Hot Reload from the CLI • An MCP server for agents 📝 Release notes: kotl.in/0.12.0-slack youtrack It’s still in Alpha, so we'd love your feedback here or on YouTrack

📣 Kotlin’s annual developer survey is out! We’d love to hear from you. Help us improve the language, tools, and overall developer experience by sharing your thoughts. 👉 Take the survey

IS KOTLIN'S GOLDEN AGE OVER?

It’s a bold question to ask @jw, someone who was there when Kotlin became an official Android language. His answer is not quite what you might expect. His takes on AI, Swift vs. Kotlin, Flutter, Gradle, open source, and the Kotlin feature that annoys him might also surprise you. Watch Jake Wharton in conversation with @Vitaly Bragilevsky👇