v2.0.0-RC1
What's New
Kotlin 2.0.0-RC1 stabilizes the K2 compiler by removing pre-release status and delivering over 200 bug fixes across Analysis API, type inference, Java interoperability, and multiplatform compilation. Major improvements include enhanced Kotlin/Wasm support with partial linkage, better diagnostic reporting for deprecations and type errors, and performance optimizations for large framework generation. This release focuses on production readiness with extensive fixes for false positives, missing diagnostics, and edge cases in generic type handling and smart casting.
Highlights
- K2 compiler reaches Release Candidate status with pre-release flag removed
- Extensive bug fixes across Analysis API, type inference, and Java interoperability
- Performance improvements in K2 compiler and Kotlin Native framework generation
- Enhanced support for Kotlin/Wasm with partial linkage and K2 integration
- Improved diagnostics for deprecation warnings, contracts, and type mismatches
- Better handling of expect/actual modifiers and multiplatform compilation
Breaking Changes
- Typealias as callable qualifier in imports now deprecated under K2
- Removed pre-release flag from K2 compiler in 2.0-RC
- Prohibited 'header' and 'impl' keywords in multiplatform projects
Deprecations
- Using typealias as a callable qualifier in imports
- KT-57014: Wrong nullability returned from JDK SAM constructor lambda
- KT-59138: Language feature changes under feature flag
Recent Releases
All releases →
v2.3.20-RC
Feb 19, 2026
Release Notes →
v2.3.10
Feb 5, 2026
Release Notes →
v2.3.10-RC2
Feb 2, 2026
Release Notes →
v2.3.20-Beta2
Jan 29, 2026
Release Notes →
v2.3.10-RC
Jan 19, 2026
Release Notes →
v2.3.20-Beta1
Jan 8, 2026
Release Notes →
v2.3.0
Dec 16, 2025
Release Notes →
v2.3.0-RC3
Dec 9, 2025
Release Notes →
v2.3.0-RC2
Dec 2, 2025
Release Notes →
v2.3.0-RC
Nov 18, 2025
Release Notes →
v2.3.0-Beta2
Oct 28, 2025
Release Notes →