Java Platform, Standard Edition 21 Reference Implementations

The official Reference Implementation for Java SE 21 (JSR 396) is based solely upon open-source code available from the JDK 21 Project in the OpenJDK Community.

The binaries are available under the GNU General Public License version 2, with the Classpath Exception.

These binaries are for reference use only!

These binaries are provided for use by implementers of the Java SE 21 Platform Specification and are for reference purposes only. This Reference Implementation has been approved through the Java Community Process. Production-ready binaries under the GPL are available from Oracle; and will be in most popular Linux distributions.

RI Binary (build 21+35) under the GNU General Public License version 2

• Oracle Linux 8.7 x64 Java Development Kit (sha256) 189 MB
• Windows 11 x64 Java Development Kit (sha256) 188 MB

RI Source Code

The source code of the RI binaries is available under the GPLv2 in a single zip file (sha256) 172 MB.

International use restrictions

Due to limited intellectual property protection and enforcement in certain countries, the JDK source code may only be distributed to an authorized list of countries. You will not be able to access the source code if you are downloading from a country that is not on this list. We are continuously reviewing this list for addition of other countries.