Java Backend Technology

May 27, 2026 · Fundamentals

JDK 27 Cuts Object Header Overhead by 33% and Reduces CPU Usage by Up to 30%

JDK 27 introduces JEP 534, making compact object headers the default layout, shrinking the 12‑byte header to 8 bytes (a 33% reduction), which lowers heap memory consumption by over 20%, cuts CPU time by 8‑30% in benchmarks, reduces GC pressure, and requires no code changes.