JEP 450 (Compact Object Headers) has been targeted for delivery in JDK 24, and has already been merged to main. This currently experimental feature optimizes heap utilization by shrinking the size of the mandatory object header in HotSpot. This should reduce overall heap size, improve density of deployments, and increase data locality. Overview of Current Implementation HotSpot stores all objects in the Java heap, a contiguous area of the "C heap" of the process. Objects in Java are always handl...