Kotlin releases

Edit pageLast modified: 01 April 2025

Latest Kotlin version: 2.1.20

See What's new in Kotlin 2.1.20 for details

Since Kotlin 2.0.0, we ship the following types of releases:

  • Language releases (2. x. 0) that bring major changes in the language and include tooling updates. Released once in 6 months.

  • Tooling releases (2. x. 20) that are shipped between language releases and include updates in the tooling, performance improvements, and bug fixes. Released in 3 months after corresponding language release.

  • Bug fix releases (2. x. yz) that include bug fixes for tooling releases. There is no exact release schedule for these releases.

For each language and tooling release, we also ship several preview (EAP) versions for you to try new features before they are released. See Early Access Preview for details.

note

If you want to be notified about new Kotlin releases, subscribe to the Kotlin newsletter, follow Kotlin on X, or enable the Watch | Custom | Releases option on the Kotlin GitHub repository.

Update to a new Kotlin version

To upgrade your project to a new release, you need to update your build script file. For example, to update to Kotlin 2.1.20, change the version of the Kotlin Gradle plugin in your build.gradle(.kts) file:

plugins {
    // Replace `<...>` with the plugin name appropriate for your target environment
    kotlin("<...>") version "2.1.20"
    // For example, if your target environment is JVM:
    // kotlin("jvm") version "2.1.20"
    // If your target is Kotlin Multiplatform:
    // kotlin("multiplatform") version "2.1.20"
}

If you have projects created with earlier Kotlin versions, change the Kotlin version in your projects and update kotlinx libraries if necessary.

If you are migrating to the new language release, Kotlin plugin's migration tools will help you with the migration.

IDE support

Even with the release of the K2 compiler, IntelliJ IDEA and Android Studio still use the previous compiler by default for code analysis, code completion, highlighting, and other IDE-related features.

Starting from 2024.1, IntelliJ IDEA can use the new K2 compiler to analyze your code with its K2 mode. To enable it, go to Settings | Languages & Frameworks | Kotlin and select the Enable K2 mode option.

Enable K2 mode

After enabling K2 mode, you may notice differences in IDE analysis due to changes in compiler behavior. Learn how the new K2 compiler differs from the previous one in the migration guide.

Kotlin release compatibility

Learn more about types of Kotlin releases and their compatibility

Release details

The following table lists details of the latest Kotlin releases:

tip

You can also try Early Access Preview (EAP) versions of Kotlin.

Build info

Build highlights

2.1.20

Released: March 20, 2025

Release on GitHub

A tooling release for Kotlin 2.1.0 containing new experimental features, performance improvements, and bug fixes.

Learn more about Kotlin 2.1.20 in What's new in Kotlin 2.1.20.

2.1.10

Released: January 27, 2025

Release on GitHub

A bug fix release for Kotlin 2.1.0

For more details, please refer to the changelog.

2.1.0

Released: November 27, 2024

Release on GitHub

A language release introducing new language features.

Learn more about Kotlin 2.1.0 in What's new in Kotlin 2.1.0.

2.0.21

Released: October 10, 2024

Release on GitHub

A bug fix release for Kotlin 2.0.20

For more details, please refer to the changelog.

2.0.20

Released: August 22, 2024

Release on GitHub

A tooling release for Kotlin 2.0.0 containing performance improvements and bug fixes. Features also include concurrent marking in Kotlin/Native's garbage collector, UUID support in Kotlin common standard library, Compose compiler updates, and support up to Gradle 8.8.

Learn more about Kotlin 2.0.20 in What's new in Kotlin 2.0.20.

2.0.10

Released: August 6, 2024

Release on GitHub

A bug fix release for Kotlin 2.0.0.

Learn more about Kotlin 2.0.0 in What's new in Kotlin 2.0.0.

2.0.0

Released: May 21, 2024

Release on GitHub

A language release with the Stable Kotlin K2 compiler.

Learn more about Kotlin 2.0.0 in What's new in Kotlin 2.0.0.

1.9.25

Released: July 19, 2024

Release on GitHub

A bug fix release for Kotlin 1.9.20, 1.9.21, 1.9.22, 1.9.23, and 1.9.24.

Learn more about Kotlin 1.9.20 in What's new in Kotlin 1.9.20.

1.9.24

Released: May 7, 2024

Release on GitHub

A bug fix release for Kotlin 1.9.20, 1.9.21, 1.9.22, and 1.9.23.

Learn more about Kotlin 1.9.20 in What's new in Kotlin 1.9.20.

1.9.23

Released: March 7, 2024

Release on GitHub

A bug fix release for Kotlin 1.9.20, 1.9.21, and 1.9.22.

Learn more about Kotlin 1.9.20 in What's new in Kotlin 1.9.20.

1.9.22

Released: December 21, 2023

Release on GitHub

A bug fix release for Kotlin 1.9.20 and 1.9.21.

Learn more about Kotlin 1.9.20 in What's new in Kotlin 1.9.20.

1.9.21

Released: November 23, 2023

Release on GitHub

A bug fix release for Kotlin 1.9.20.

Learn more about Kotlin 1.9.20 in What's new in Kotlin 1.9.20.

1.9.20

Released: November 1, 2023

Release on GitHub

A feature release with Kotlin K2 compiler in Beta and Stable Kotlin Multiplatform.

Learn more in:

1.9.10

Released: August 23, 2023

Release on GitHub

A bug fix release for Kotlin 1.9.0.

Learn more about Kotlin 1.9.0 in What's new in Kotlin 1.9.0.

note

For Android Studio Giraffe and Hedgehog, the Kotlin plugin 1.9.10 will be delivered with upcoming Android Studios updates.

1.9.0

Released: July 6, 2023

Release on GitHub

A feature release with Kotlin K2 compiler updates, new enum class values function, new operator for open-ended ranges, preview of Gradle configuration cache in Kotlin Multiplatform, changes to Android target support in Kotlin Multiplatform, preview of custom memory allocator in Kotlin/Native.

Learn more in:

1.8.22

Released: June 8, 2023

Release on GitHub

A bug fix release for Kotlin 1.8.20.

Learn more about Kotlin 1.8.20 in What's new in Kotlin 1.8.20.

1.8.21

Released: April 25, 2023

Release on GitHub

A bug fix release for Kotlin 1.8.20.

Learn more about Kotlin 1.8.20 in What's new in Kotlin 1.8.20.

note

For Android Studio Flamingo and Giraffe, the Kotlin plugin 1.8.21 will be delivered with upcoming Android Studios updates.

1.8.20

Released: April 3, 2023

Release on GitHub

A feature release with Kotlin K2 compiler updates, AutoCloseable interface and Base64 encoding in stdlib, new JVM incremental compilation enabled by default, new Kotlin/Wasm compiler backend.

Learn more in:

1.8.10

Released: February 2, 2023

Release on GitHub

A bug fix release for Kotlin 1.8.0.

Learn more about Kotlin 1.8.0.

note

For Android Studio Electric Eel and Flamingo, the Kotlin plugin 1.8.10 will be delivered with upcoming Android Studios updates.

1.8.0

Released: December 28, 2022

Release on GitHub

A feature release with improved kotlin-reflect performance, new recursively copy or delete directory content experimental functions for JVM, improved Objective-C/Swift interoperability.

Learn more in:

1.7.21

Released: November 9, 2022

Release on GitHub

A bug fix release for Kotlin 1.7.20.

Learn more about Kotlin 1.7.20 in What's new in Kotlin 1.7.20.

note

For Android Studio Dolphin, Electric Eel, and Flamingo, the Kotlin plugin 1.7.21 will be delivered with upcoming Android Studios updates.

1.7.20

Released: September 29, 2022

Release on GitHub

An incremental release with new language features, the support for several compiler plugins in the Kotlin K2 compiler, the new Kotlin/Native memory manager enabled by default, and the support for Gradle 7.1.

Learn more in:

Learn more about Kotlin 1.7.20.

1.7.10

Released: July 7, 2022

Release on GitHub

A bug fix release for Kotlin 1.7.0.

Learn more about Kotlin 1.7.0.

note

For Android Studio Dolphin (213) and Android Studio Electric Eel (221), the Kotlin plugin 1.7.10 will be delivered with upcoming Android Studios updates.

1.7.0

Released: June 9, 2022

Release on GitHub

A feature release with Kotlin K2 compiler in Alpha for JVM, stabilized language features, performance improvements, and evolutionary changes such as stabilizing experimental APIs.

Learn more in:

1.6.21

Released: April 20, 2022

Release on GitHub

A bug fix release for Kotlin 1.6.20.

Learn more about Kotlin 1.6.20.

1.6.20

Released: April 4, 2022

Release on GitHub

An incremental release with various improvements such as:

  • Prototype of context receivers

  • Callable references to functional interface constructors

  • Kotlin/Native: performance improvements for the new memory manager

  • Multiplatform: hierarchical project structure by default

  • Kotlin/JS: IR compiler improvements

  • Gradle: compiler execution strategies

Learn more about Kotlin 1.6.20.

1.6.10

Released: December 14, 2021

Release on GitHub

A bug fix release for Kotlin 1.6.0.

Learn more about Kotlin 1.6.0.

1.6.0

Released: November 16, 2021

Release on GitHub

A feature release with new language features, performance improvements, and evolutionary changes such as stabilizing experimental APIs.

Learn more in:

1.5.32

Released: November 29, 2021

Release on GitHub

A bug fix release for Kotlin 1.5.31.

Learn more about Kotlin 1.5.30.

1.5.31

Released: September 20, 2021

Release on GitHub

A bug fix release for Kotlin 1.5.30.

Learn more about Kotlin 1.5.30.

1.5.30

Released: August 23, 2021

Release on GitHub

An incremental release with various improvements such as:

  • Instantiation of annotation classes on JVM

  • Improved opt-in requirement mechanism and type inference

  • Kotlin/JS IR backend in Beta

  • Support for Apple Silicon targets

  • Improved CocoaPods support

  • Gradle: Java toolchain support and improved daemon configuration

Learn more in:

1.5.21

Released: July 13, 2021

Release on GitHub

A bug fix release for Kotlin 1.5.20.

Learn more about Kotlin 1.5.20.

1.5.20

Released: June 24, 2021

Release on GitHub

An incremental release with various improvements such as:

  • String concatenation via invokedynamic on JVM by default

  • Improved support for Lombok and support for JSpecify

  • Kotlin/Native: KDoc export to Objective-C headers and faster Array.copyInto() inside one array

  • Gradle: caching of annotation processors' classloaders and support for the --parallel Gradle property

  • Aligned behavior of stdlib functions across platforms

Learn more in:

1.5.10

Released: May 24, 2021

Release on GitHub

A bug fix release for Kotlin 1.5.0.

Learn more about Kotlin 1.5.0.

1.5.0

Released: May 5, 2021

Release on GitHub

A feature release with new language features, performance improvements, and evolutionary changes such as stabilizing experimental APIs.

Learn more in:

1.4.32

Released: March 22, 2021

Release on GitHub

A bug fix release for Kotlin 1.4.30.

Learn more about Kotlin 1.4.30.

1.4.31

Released: February 25, 2021

Release on GitHub

A bug fix release for Kotlin 1.4.30

Learn more about Kotlin 1.4.30.

1.4.30

Released: February 3, 2021

Release on GitHub

An incremental release with various improvements such as:

  • New JVM backend, now in Beta

  • Preview of new language features

  • Improved Kotlin/Native performance

  • Standard library API improvements

Learn more in:

1.4.21

Released: December 7, 2020

Release on GitHub

A bug fix release for Kotlin 1.4.20

Learn more about Kotlin 1.4.20.

1.4.20

Released: November 23, 2020

Release on GitHub

An incremental release with various improvements such as:

  • Supporting new JVM features, like string concatenation via invokedynamic

  • Improved performance and exception handling for Kotlin Multiplatform Mobile projects

  • Extensions for JDK Path: Path("dir") / "file.txt"

Learn more in:

1.4.10

Released: September 7, 2020

Release on GitHub

A bug fix release for Kotlin 1.4.0.

Learn more about Kotlin 1.4.0.

1.4.0

Released: August 17, 2020

Release on GitHub

A feature release with many features and improvements that mostly focus on quality and performance.

Learn more in:

1.3.72

Released: April 15, 2020

Release on GitHub

A bug fix release for Kotlin 1.3.70.

Learn more about Kotlin 1.3.70.