AEM CS & Support for Java 25

Earlier this year the switch to Java 21 was completed for AEM CS and support for earlier versions of Java has been discontinued (see my blog post on that topic). It was a bit of a bumpy road to get there…

Java 25, the next LTS version, has been released a year ago in September 2025, and the roadmap for its adoption in AEM as a Cloud Service has been released already in June (Release Notes).

• October 2026: The SDK will support Java 25
• November 2026: You can enable Java 25 support for you AEM CS environments in Cloud Manager
• February/March 2027: Start of slow migrations of RDE and DEV environments to use a Java 25 runtime
• June 2027: All environments are migrated to Java 25, and the runtime support for Java 21 will be discontinued for AEM CS.

For that reason I recommend you to include this migration into your schedule. The gap is smaller than the last migration from Java 11 and 21, and I expect that only the “usual suspects” need to be updated, which need to support the latest versions of the class format (that means: mostly ASM and all the libraries which depend on ASM…. groovy, I am looking on you!).

And while we are talking about Java versions; Cloud Manager still supports Java 8 for builds…. Personally I would be more than happy if all of you could switch to a newer build version, even if just for a single reason: Builds with Java 21 are much faster than with Java 11 or 8 (my rule of thumb: 100% faster).

And yes, when Java 29 will be released next year, we will do this exercise again 🙂