That's one hefty release!

Kotlin 1.3 is out: Coroutines graduate to stable, plus betas for Kotlin/Native & Ktor 1.0

Gabriela Motroc
Kotlin 1.3
© Shutterstock / serazetdinov

We’ve been talking about coroutines for the past three months and now they are finally here (and stable!). But that’s not all Kotlin 1.3 has to offer; it arrives with a bunch of libraries, build tools, and learning materials in tow. Let’s have a closer look at what’s included in this release.

Kotlin 1.3 is here. This release includes a lot of goodies but if we were to summarize it, we would include the following milestones:

  • Coroutines are now stable
  • Kotlin/Native has reached Beta
  • Multiplatform projects are moving forward (still an experimental feature though!)
  • Ktor 1.0  has reached Beta

You can read the full description on the What’s New page or check out the changelog here. There’s also a blog post detailing the highlights and the compatibility guide can be found here.

You can give Kotlin a try online at

  • In Maven, Gradle and npm: Use 1.3.0 as the version number for the compiler and the standard library. See the docs here.
  • In IntelliJ IDEA: 2018.3 has Kotlin 1.3 bundled, in earlier versions Install or update the Kotlin plugin to version 1.3.
  • In Android Studio: Install or update the plugin through Plugin Manager.
  • In Eclipse: install the plugin using Marketplace.
  • The command-line compiler can be downloaded from the Github release page.

Kotlin 1.3 highlights


We’ve been talking about coroutines since July 2018 and now this feature is finally here. This means that the language support and the API are fully stable.

This tool will come in handy if you want to offload work onto background workers or implement complicated network protocols. The kotlinx.coroutines library hits 1.0 release and provides a solid foundation for managing asynchronous jobs at any scale including composition, cancelation, exception handling and UI-specific use cases, as explained in the blog post detailing the highlights.

If you’re not entirely sure what coroutines are and how you can use them, check out the brand new coroutines overview page.

Kotlin/Native reaches beta

If you wish to compile Kotlin code to native binaries, you’ll need Kotlin/Native. This technology uses LLVM to compile Kotlin sources to standalone binaries (no VM required!) for a bunch of operating systems and CPU architectures including iOS, Linux, Windows, Mac and even WebAssembly and embedded systems like STM32.

In short, “it solves the situations when a developer needs to produce a self-contained program that does not require an additional runtime or virtual machine.” For more details about its advantages, check out the Kotlin/Native overview.

Multiplatform projects and tooling

The Kotlin team has completely reworked the model of multiplatform projects with the purpose of improving expressiveness and flexibility, and making sharing common code easier. Since we just mentioned Kotlin/Native, you should know that it’s also supported as one of the targets.  Read more about multiplatform programming here.

 Keep in mind that even though progress [in the form of multiplatform libraries shipped with the latest release] has been made, multiplatform capabilities in Kotlin are still experimental.

Kotlin 1.3 arrives with tooling support for Kotlin/Native and Multiplatform projects in tow, which is now available in IntelliJ IDEA Community Edition, IntelliJ IDEA Ultimate, and Android Studio. It’s worth mentioning that all code editing features such as error highlighting, code completion, navigation and refactoring are available in all the three IDEs.

Ktor 1.0 beta

Ktor, JetBrains’ connected applications framework which implements the entire HTTP stack fully asynchronously using coroutines, has reached Beta and is available at

Other features and improvements

Don’t forget to check out the What’s New in Kotlin 1.3 page for more details about the goodies shipped with the latest release.

Gabriela Motroc
Gabriela Motroc was editor of and JAX Magazine. Before working at Software & Support Media Group, she studied International Communication Management at the Hague University of Applied Sciences.

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