Kotlin Multiplatform v2.2.0-Beta1 Release Notes & Developer Guide
What's New for Developers
Kotlin v2.2.0-Beta1 stabilizes context parameters across the compiler and Analysis API while enabling JVM default interface methods by default. This release includes 50+ bug fixes for K2 compiler reliability, significant performance improvements in symbol resolution and caching, and enhanced WebAssembly support. Mobile developers will benefit from improved IDE responsiveness and more accurate type inference in complex scenarios.
Highlights
- Context parameters now fully supported in K2 compiler with improved resolution and API surface
- JVM default interface methods enabled by default with -Xjvm-default=all-compatibility
- Unnamed local variables support reduces boilerplate in Kotlin code
- Analysis API performance improvements including optimized symbol providers and caching
- WebAssembly backend enhancements for annotation instantiation and floating-point consistency
- K2 compiler stability improvements with 50+ bug fixes for type inference and diagnostics
Breaking Changes
- Language versions 1.8 and 1.9 deprecated, migrate to 2.0 or later
- JVM default interface methods now generated by default, may affect binary compatibility with older JVM targets
Deprecations
- kotlin.concurrent.AtomicRef<Int> deprecated in favor of new atomics library
- Extended compiler checks (-Xextended-compiler-checks) deprecated with planned removal
Recent Releases
All releases →
v2.5.0-Beta2
Oct 21, 2026
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v2.4.21
Oct 8, 2026
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v2.4.21-RC
Sep 30, 2026
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v2.5.0-Beta1
Sep 23, 2026
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v2.4.20
Sep 7, 2026
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v2.4.20-RC3
Sep 2, 2026
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v2.4.20-RC2
Aug 26, 2026
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v2.4.20-RC
Aug 12, 2026
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v2.4.20-Beta2
Jul 22, 2026
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v2.4.10
Jul 14, 2026
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v2.4.10-RC2
Jul 7, 2026
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