Kotlin Multiplatform v2.3.20-Beta2 Release Notes & Developer Guide
What's New for Developers
Kotlin v2.3.20-Beta2 delivers significant improvements to collection literals, JavaScript ES6 support, and Java interoperability while stabilizing explicit backing fields and Swift Export. The release includes critical bug fixes for reflection, annotation handling, and multi-target compilation, plus enhanced Gradle compatibility up to version 9.3.0 with new JPA plugin support.
Highlights
- Collection literals now resolve to standard library factory functions with improved type support
- ES6 features in js() calls: default arguments, classes, spread operators, rest parameters
- Enhanced Java interoperability with JSpecify annotations and improved null safety handling
- Performance improvements in Analysis API with PSI-based implementations and reduced casts
- Gradle 9.3.0 compatibility and new JPA preset for allopen plugin
- Swift Export fixes for varargs, generics, and property visibility
- Explicit backing fields stability improvements and intersection override support
Breaking Changes
- Inline functional context parameters in inline functions are now forbidden
- Out-of-process compilation mode in Gradle is deprecated and will be removed
- PreprocessedVirtualFileFactoryExtension compiler plugin API is deprecated
Deprecations
- KaSymbolInformationProvider getter and setter deprecation status methods
- CleanableStore infrastructure in Gradle plugin
- androidTarget deprecation reverted for AGP versions lower than 9
Recent Releases
All releases →
v2.5.0-Beta2
Oct 21, 2026
Release Notes →
v2.4.21
Oct 8, 2026
Release Notes →
v2.4.21-RC
Sep 30, 2026
Release Notes →
v2.5.0-Beta1
Sep 23, 2026
Release Notes →
v2.4.20
Sep 7, 2026
Release Notes →
v2.4.20-RC3
Sep 2, 2026
Release Notes →
v2.4.20-RC2
Aug 26, 2026
Release Notes →
v2.4.20-RC
Aug 12, 2026
Release Notes →
v2.4.20-Beta2
Jul 22, 2026
Release Notes →
v2.4.10
Jul 14, 2026
Release Notes →
v2.4.10-RC2
Jul 7, 2026
Release Notes →