v1.9.0
What's New
Kotlin 1.9.0 delivers K2 compiler alpha support for multiplatform development with enhanced Analysis API extensibility and improved stability across JVM, Native, and Wasm backends. The release includes new language features like secondary constructors in value classes and Volatile annotation support for Native, alongside significant performance optimizations and hundreds of bug fixes addressing K2 compiler issues, partial linkage scenarios, and cross-platform compatibility.
Highlights
- K2 compiler reaches alpha support for multiplatform projects with improved stability
- Analysis API now supports extending Kotlin resolution with new extensibility mechanisms
- Value classes now support secondary constructors with function bodies
- Volatile annotation support added for Kotlin/Native
- Kotlin/Wasm gains restricted JS interop with external type validation
- Significant compiler performance improvements and bug fixes across all backends
Breaking Changes
- JvmDefault annotation and old -Xjvm-default modes deprecated with ERROR level
- Method deprecation no longer propagates through overrides
- Actual members in expect classes now forbidden
Deprecations
- JvmDefault annotation deprecated with ERROR
- -Xjvm-default modes (all, all-compatibility) deprecated with ERROR
- Anonymous type exposure from inline functions with type arguments deprecated
Recent Releases
All releases →
v1.9.0
Jul 6, 2023
Release Notes →
v1.8.22
Jun 8, 2023
Release Notes →
v1.8.21
Apr 25, 2023
Release Notes →
v1.8.20
Apr 3, 2023
Release Notes →
v1.8.10
Feb 2, 2023
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v1.8.0
Dec 28, 2022
Release Notes →
v1.7.22
Nov 28, 2022
Release Notes →
v1.7.21
Nov 9, 2022
Release Notes →
v1.7.20
Sep 29, 2022
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v1.7.10
Jul 8, 2022
Release Notes →
v1.7.0
Jun 9, 2022
Release Notes →