v1.9.0-Beta
What's New
Kotlin v1.9.0-Beta advances K2 compiler maturity with alpha multiplatform support, enhanced Analysis API for IDE tooling, and critical fixes for type inference, suspend functions, and cross-platform compilation. Kotlin/Wasm gains JS interop capabilities while Native debugging improves with inline function parameter visibility. The release includes 100+ compiler fixes addressing partial linkage, annotation handling, and dynamic type resolution.
Highlights
- K2 compiler reaches alpha support for multiplatform projects with improved cross-platform compatibility
- Analysis API extended with new resolution capabilities and improved symbol restoration from PSI
- Kotlin/Wasm gains restricted JS interop support and fixes for external function overrides
- Secondary constructors now supported in value classes with function bodies
- K2 type inference improvements for builder patterns, generics, and suspend functions
- Native debugger now displays inline function parameters during debugging sessions
Breaking Changes
- JvmDefault annotation and old -Xjvm-default modes deprecated with ERROR level
- Range/Progression Collection implementation may cause overload resolution changes in future versions
Deprecations
- JvmDefault annotation and legacy -Xjvm-default compiler modes
- Number.toChar() method deprecated for integer cinterop conversions
- Anonymous type exposure from inline functions with type arguments
Recent Releases
All releases →
v2.3.20-RC
Feb 19, 2026
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v2.3.10
Feb 5, 2026
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v2.3.10-RC2
Feb 2, 2026
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v2.3.20-Beta2
Jan 29, 2026
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v2.3.10-RC
Jan 19, 2026
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v2.3.20-Beta1
Jan 8, 2026
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v2.3.0
Dec 16, 2025
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v2.3.0-RC3
Dec 9, 2025
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v2.3.0-RC2
Dec 2, 2025
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v2.3.0-RC
Nov 18, 2025
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v2.3.0-Beta2
Oct 28, 2025
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