OpenJDK News Roundup: Vector API, Compact Object Headers and G1GC as Default in JDK 27
InfoQ, Monday, May 25th, 2026
JDK 27 targets Vector API, Compact Object Headers, and G1GC as default garbage collector with a September 2026 release.
OpenJDK announced three major JEPs targeted for JDK 27: JEP 537 continues the Vector API's incubation for optimized vector computations, JEP 534 makes Compact Object Headers the default layout in HotSpot JVM, and JEP 523 sets G1 Garbage Collector as the default in all environments.
Additionally, three other JEPs were proposed for targeting including PEM Encodings for cryptographic objects, JFR data redaction, and post-mortem crash analysis via jcmd. The JDK 27 release is scheduled for September 14, 2026, with the feature set freezing on June 4, 2026 during Rampdown Phase One.