Subscription to Innovation: Java 21 Support

In the ever-evolving landscape of application development, where security is top-of-mind, keeping up with the latest versions of supporting systems is essential.

Mendix heavily relies on Java as its foundation, so it’s imperative for businesses to stay up-to-date with new supported versions. In this blog post, we’ll delve into Mendix’s Java support journey, focusing on our plan to incorporate Java 17 in Mendix 9 and 10 – and Java 21 in Mendix 9 and 10.

Since our last update, support for Java 11 has been extended, lowering the pressure to update to stay compliant. We have updated the text and dates in this blog post to reflect the current situation.

Support for new Java versions

Currently, Mendix supports Java 11, a long-term support (LTS) version. Originally, support for Java 11 would conclude in October 2024, but that has recently been changed to October 2027. We still advise customers to transition to newer LTS versions, namely Java 17 and 21.

Over the next six months, we will introduce support for Java 17 and Java 21 in Mendix 9, and 10. Java 17 and 21 enjoy official support until October 2027 and September 2029, respectively.

Here’s a breakdown of the compatibility between Mendix and Java versions during their lifecycle:

Java 21 Update

*Optional: we recommend that you skip Java 17 and jump to Java 21 once it’s supported.

As Mendix 10 releases every month, Mendix 10.8 will run on Java 17, and Mendix 10.10 will add Java 21 compatibility. As soon as Java 17 support is released we’ll also backport that to the 10.6 MTS release.

Transitioning to a new Java version

Just as Mendix made the seamless transition from Java 8 to 11, the move to Java 17 or 21 is expected to be equally smooth.

Both Java 17 and 21 maintain compatibility with older language constructs, such as those found in Java 8 and 11. While some exceptions might affect the Mendix Runtime internals, most customer apps on Java 17 or 21 won’t experience any functional changes. Moreover, the introduction of Java 17 and 21 support allows developers to harness newer language constructs.

What does this mean for you?

Version timeline

To stick with a supported Java version, you will need to update your app before October 2027, after compatibility has been added by Mendix.

  • Mendix 10: switch to Java 21 with 10.10 from April 2024.
  • Mendix 9: switch to Java 21 with a new patch version from June 2024.


For developing in Studio Pro, you won’t need to do anything. Mendix will install a new version of the JDK when support has been added. Per project, you can indicate which Java version you want to run your app on.


If your apps are deployed to the Mendix Cloud, you don’t have to worry about the underlying Java version. We will ensure apps run with Java 17 and 21 for Mendix versions that support that.

Mendix 11: The end of Java 17 support

With our next major version Mendix 11, scheduled to release in June 2025, we will already drop support for Java 17. This allows us to use the newest versions of Java in the Mendix platform, to offer the best possible experience.

Staying up-to-date

Mendix’s commitment to staying up-to-date with the latest Java versions ensures that companies can always use an officially supported Java version while allowing developers to leverage the advantages of new features in Java. With the transition to Java 17 and 21, Mendix empowers developers to create secure, cutting-edge applications that harness the full potential of the Java ecosystem.