Kotlin Help

Kotlin Language Server

The Kotlin Language Server is JetBrains' official implementation of the Language Server Protocol (LSP) for Kotlin.

The server is based on IntelliJ IDEA, the IntelliJ IDEA Kotlin plugin, JetBrains AIR, and Fleet. It is designed to work with any code editor that supports LSP.

Kotlin in Visual Studio Code

Kotlin Language Server provides official Kotlin language support for Visual Studio Code.

If you use Visual Studio Code for Kotlin development, install the official Kotlin by JetBrains extension from the Visual Studio Marketplace.

To activate the Kotlin by JetBrains extension, open a Kotlin project in Visual Studio Code, and then open any Kotlin file.

Supported features

The Kotlin Language Server includes core language features such as:

  • Support for up-to-date Kotlin language versions

  • IntelliJ-powered code completion

  • IntelliJ-powered diagnostics and quick fixes for Kotlin and kotlinx.* libraries

  • Build system support for JVM projects: Gradle, Maven, and experimental Android Gradle Plugin support

  • Semantic highlighting

  • Organize imports

  • Rename refactoring

  • Code formatting

  • Documentation navigation and hover support

  • Call hierarchy

  • Code folding

Feedback

The Kotlin Language Server is under active development, and feedback is especially valuable during the Alpha stage.

If you run into problems or want to suggest improvements, report them in the Kotlin LSP repository.

What's next?

21 May 2026