Why Java’s Nashorn Engine Is Being Removed in JDK 15 (JEP 372 Explained)

Oracle software R&D director Jim Laskey has put forward JEP 372, a candidate Java Enhancement Proposal that aims to remove the long‑standing Nashorn JavaScript engine, its related APIs, and the jjs tool. This is the first JEP to enter the candidate stage in 2020 and is considered mature enough for inclusion in JDK 15.

JEP 372 (JEP 372) states that the Nashorn engine was originally integrated into JDK 8 via JEP 174 to replace the Rhino script engine, providing a full implementation of the ECMAScript‑262 5.1 standard. Over time, the rapid evolution of ECMAScript and its APIs made Nashorn difficult to maintain.

The proposal specifies that two JDK modules will be permanently removed: jdk.scripting.nashorn: contains jdk.nashorn.api.scripting and

jdk.nashorn.api.tree

jdk.scripting.nashorn.shell

: contains the jjs tool

This deprecation will not affect the javax.script API in any way.

When Nashorn was released, its performance was 2–10 times better than the previous Rhino implementation, which contributed to its wide adoption.

However, Nashorn was already deprecated in JDK 11 (JEP 335). JEP 372 argues that enough time has passed for developers to migrate away from it.

Developers have mixed opinions: some argue that Java’s strong backward‑compatibility should prevent removal, others criticize continued use of Rhino, and some recommend switching directly to GraalVM for a more complete and faster JavaScript/Node implementation.