Flutter and Kotlin are not directly comparable, as Flutter is a framework for building cross-platform mobile apps, and Kotlin is a programming language primarily used for developing Android apps. However, here are some key differences between the two:

Language : Flutter uses Dart, a language developed by Google, while Kotlin is a programming language developed by JetBrains.

Platform support : Flutter allows for building apps for both Android and iOS platforms, while Kotlin is primarily used for developing Android apps.

Development workflow : Flutter's "hot reload" feature allows developers to see changes to the code immediately reflected in the app, making the development process faster and more efficient. Kotlin does not have a similar feature.

UI Components : Flutter has a rich set of customizable UI components, including Material Design and Cupertino widgets, which allows for more design flexibility. Kotlin requires developers to use the native Android UI toolkit.

Performance : Flutter apps are typically faster and more responsive than native Android apps built with Kotlin, due to the fact that Flutter uses a compiled programming language and a custom rendering engine that allows for smoother animations and transitions.