How does Kotlin handle runtime performance compared to Java at JVM level?

Kotlin performance is generally comparable to Java because both compile to JVM bytecode, but Kotlin adds abstraction overhead in some constructs.

At the JVM level, Kotlin and Java execute the same bytecode, meaning raw execution speed is equivalent. Differences arise from Kotlin features like lambdas, inline functions, null safety checks, and extension functions. Kotlin reduces boilerplate but may introduce additional method calls or wrapper objects unless optimized via inlining. The Kotlin compiler aggressively optimizes these cases using inlining, constant folding, and smart casting, often eliminating overhead entirely in production builds.