Swift vs Kotlin: A Comparison from a Developer Who Uses Both

I’ve spent a good while in Android development, and lately I’ve been picking up Swift more for iOS projects. I get asked often, “which one’s better?” — the answer is: it depends on what you’re prioritizing.

Syntax & ergonomics. Both are modern and null-safe. Kotlin has sealed class and data classes that are very expressive for modeling state. Swift has enum with associated values that’s similar but works a bit differently, plus optional chaining that feels very natural to use.

Tooling. Android Studio (built on IntelliJ) for Kotlin feels more mature and stable than Xcode for Swift, at least in my experience — Xcode still crashes or slows down often as a project grows.

Concurrency. Kotlin Coroutines is one of my favorite things — simple but powerful for async code. Swift’s async/await is relatively newer (compared to Kotlin Coroutines) but is quite solid now.

Ecosystem. The Android SDK has more third-party library options because its developer base is larger. iOS’s ecosystem is more controlled but sometimes more limited.

My takeaway: if you can only pick one to learn first, start with whichever platform is more relevant to your target users. But if you can do both, each one will make you a more well-rounded mobile developer.