Kotlin Multiplatform v1.7.0-Beta Release Notes & Developer Guide

Kotlin 1.7.0-Beta delivers significant performance improvements across all platforms through compiler optimizations, enhanced FIR type inference, and runtime improvements like concurrent GC for Native. The release modernizes the toolchain by removing legacy JVM targets and deprecated APIs while adding new stdlib features for Optional handling and regex support. Developers targeting multiplatform projects benefit from improved cinterop commonization and better IDE integration.

Highlights

• Kotlin/Native: Concurrent Sweep GC enabled by default for improved memory management
• JavaScript IR: Member name minimization in production mode reduces bundle size
• Extensive compiler optimizations for loops, enums, and null checks improve performance
• FIR compiler improvements: better type inference and resolution for complex expressions
• Native debugging enhanced with improved error display in variables view
• Stdlib additions: Optional extensions, CPU count API, named regex capture groups