Benchmark 2025: Performance Comparison of Kotlin with Java, Go, and Rust

Kotlin vs Competitors in 2025: Who is Faster, Lighter, and More Efficient?

In 2025, Kotlin firmly holds its position as one of the most in-demand languages for server-side and mobile development. However, to stay on top, it has to compete with recognized performance leaders — Java, Go, and Rust. Fresh benchmarks published in February 2025 shed light on the real balance of power. We break down the key metrics: execution speed, memory consumption, and compilation speed.

Testing Methodology

The tests were conducted on identical hardware (AMD Ryzen 9 7950X, 64 GB RAM, Linux 6.8) for the following tasks:

• JSON serialization/deserialization (10,000 complex objects);
• Floating-point calculations (Mandelbrot algorithm);
• Multithreading (thread pool, 1 million tasks);
• Compilation cold start and incremental build.

Execution Performance: Rust Leads, Kotlin Close Behind

In CPU-intensive tasks, the traditional leader — Rust — showed the best results, outperforming Kotlin by 15–20%. However, Kotlin (JVM) surprised: thanks to JIT compiler optimizations in JDK 22, it almost caught up with Go in calculations, and in JSON parsing it even showed a result 5% better than Go. Java remained in third place, losing to Kotlin by about 8% in multithreading tests due to the more cumbersome coroutine syntax.

Memory Consumption: Efficiency of Kotlin Native

Here, the main surprise came from Kotlin/Native. When compiled to native code (without JVM), it consumes on average 30% less RAM than Go and 40% less than Java. Rust remains unmatched in minimal memory usage, but Kotlin/Native confidently takes second place, making it an excellent choice for microservices and edge devices.

Compilation Speed: Go is the King of Fast Builds

• Go: 2.1 seconds (cold build) — undisputed leader.
• Rust: 8.4 seconds — slowest due to its complex type system and LLVM.
• Kotlin (JVM): 4.7 seconds — a 12% improvement compared to 2024 thanks to the new K2 compiler.
• Java: 4.2 seconds — still faster than Kotlin, but the gap is narrowing.

Conclusions: Who to Choose in 2025?

The benchmark showed that Kotlin has become a universal soldier: it is not inferior to Java in performance, surpasses Go in flexibility (coroutines, DSL), and offers native compilation for scenarios where memory is critical. Rust remains the best for hardcore low-level programming, and Go for rapid prototyping and infrastructure utilities. For web backends, Android, and microservices in 2025, Kotlin is the optimal balance of speed, memory, and development convenience.

Full tables and test source code are available in the project repository on GitHub. Stay tuned for updates on PythonLib!