Kotlin 2.3 adds new language features, native interop updates, Java 25 support, and more

JetBrains has announced the release of Kotlin 2.3.0, bringing a mix of new language features, increased default stability, and essential updates across its cross-platform programming language. Users will find improved core language capabilities, including more features made stable or enabled by default, an unused return value checker, explicit backing fields, and refined context-sensitive resolution rules.

Alongside broad language improvements, Kotlin 2.3 expands its JVM support to include Java 25, broadening applicability for developers working with the latest Java platform. For native development, the update delivers better interoperability with Apple’s Swift through enhanced export options, faster release build times, and the addition of beta support for importing C and Objective-C libraries.

On the WebAssembly front, users receive fully qualified names and a new exception handling proposal enabled by default, plus a compact storage format for Latin-1 characters. JavaScript users benefit from experimental suspend function export, a revised LongArray representation, and a unified approach to accessing companion objects.

Gradle integration is also improved, with Kotlin’s Gradle plugin now supporting Gradle 9.0 and introducing an API for generated source registration. Additional updates include stack traces for minified Android apps in the Compose compiler, as well as stabilized time tracking and enhanced UUID functionality in the standard library.