JDK 23 Release Highlights and Upgrade Considerations

JDK 23 was officially released on 2024‑09‑17. It is a non‑LTS release; the next LTS version will be JDK 25, expected in September 2025. Current LTS releases are JDK 1.8, 11, 17 and 21.

According to global market data, JDK 17 holds the largest share (35.4 %) in 2024, while in China JDK 1.8 likely remains dominant.

New features in JDK 23

Most of the new additions are preview APIs, including pattern matching for primitive types (JEP 455), a second preview of the class‑file API, Markdown doc comments, the eighth incubator of the Vector API, a second preview of stream collectors, deprecation of unsafe memory‑access methods, ZGC’s default generational mode, module‑import declarations, implicit classes and main methods, structured concurrency, scoped values, and flexible constructor bodies.

Features that have become standard are Markdown doc comments, the deprecation of the unsafe memory‑access methods, and ZGC’s default generational mode, which improves garbage‑collection performance.

Should you upgrade?

Upgrading decisions depend on project context. Enterprise projects prioritize stability and may avoid non‑LTS releases, while personal projects consider ecosystem support such as Spring Boot compatibility.