Kotlin 2.4 lands with stable context parameters, Java 26 support, UUID API & Swift support

JetBrains has released Kotlin 2.4, introducing stable context parameters and explicit backing fields to the cross-platform programming language. Alongside these language improvements, the release adds multiple features targeting annotation use-site scenarios. These changes help developers write clearer and more maintainable code across platforms.

In the standard library, Kotlin 2.4 brings stabilized support for the universally unique identifier (UUID) API and adds the ability to check if collections are sorted. Kotlin users gain support for Java 26 and benefit from annotation emission in metadata, now enabled by default.

Kotlin advances interoperability by supporting Swift packages as dependencies, making iOS and macOS development smoother, and enables the concurrent mark-sweep (CMS) garbage collector by default. Incremental compilation is now turned on by default, with new support for the WebAssembly Component Model. Following these changes, Kotlin now exports value classes and brings ES2015 features to JavaScript code inlining.

On the build tool side, Kotlin 2.4 supports Gradle 9.5.0 and enables automatic Java and JVM version alignment in Maven projects. The Kotlin compiler delivers more consistent behavior for inline functions during .klib compilation.