Java 21

Status	Long Term Support Release
Release Date	2023-09-19
EOL Date	2029-12
Latest Version	21.0.8
Umbrella JSR	JSR 396
Class File Version	65.0
Unicode Version	15.0.0
API Changes	Compare to 20 - 19 - 18 - 17 - 16 - 15 - 14 - 13 - 12 - 11 - 10 - 9 - 8 - 7 - 6 - 5 - 1.4 - 1.3 - 1.2 - 1.1 - 1.0
Documentation	Release Notes, Language Spec, VM Spec, JavaDoc
SCM	git

Data Source

Java 21 is a current long term support (LTS) release.

New Features

Here are all new features in Java 21 by category. There is also of list of all features of all Java releases.

JVM

Generational ZGC (JEP 439)
Deprecate the Windows 32-bit x86 Port for Removal (JEP 449)
Prepare to Disallow the Dynamic Loading of Agents (JEP 451)

Language

String Templates 1. Preview (JEP 430, Java Almanac)
Record Patterns (JEP 440, Java Almanac)
Pattern Matching for switch (JEP 441, Java Almanac)
Unnamed Patterns and Variables 1. Preview (JEP 443)
Unnamed Classes and Instance Main Methods 1. Preview (JEP 445, Java Almanac)

API

Sequenced Collections (JEP 431)
Foreign Function & Memory API 3. Preview (JEP 442)
Virtual Threads (JEP 444, Java Almanac)
Scoped Values 1. Preview (JEP 446)
Vector API 6. Incubator (JEP 448)
Key Encapsulation Mechanism API (JEP 452)
Structured Concurrency 1. Preview (JEP 453)

Should I Upgrade?

With Java 21 you're running on a actively maintained long term support (LTS) version - which is good. The currently planned end-of-life date for this version within the OpenJDK project is 2029-12.

However, you might consider upgrading to a newer LTS version Java 25 to get advantage of the latest features and improvements.

Downloads

Vendor	Product	License	Platform Downloads
Adoptium	Eclipse Temurin	GPLv2+CE	aix-ppc64 alpine-arm64 alpine-x64 linux-arm64 linux-ppc64le linux-riscv64 linux-s390x linux-x64 macos-arm64 macos-x64 windows-arm64 windows-x64
Amazon	Corretto 21	GPLv2+CE	alpine-arm64 alpine-x64 linux-arm64 linux-x64 macos-arm64 macos-x64 windows-x64
Azul Systems	Zulu Builds of OpenJDK 21	GPLv2+CE	alpine-arm64 alpine-x64 linux-arm64 linux-x64 macos-arm64 macos-x64 windows-arm64 windows-x64
Azul Systems	Azul Prime	Commercial	linux-x64 linux-arm64
BellSoft	Liberica	GPLv2+CE	alpine-arm64 alpine-x64 linux-arm32 linux-arm64 linux-ppc64le linux-riscv64 linux-x86 linux-x64 macos-arm64 macos-x64 windows-arm64 windows-x86 windows-x64
IBM	Semeru Runtime Open Edition, Version 21	GPLv2+CE	aix-ppc64 linux-arm64 linux-ppc64le linux-s390x linux-x64 macos-arm64 macos-x64 windows-x64
Microsoft	Microsoft Build of OpenJDK 21	GPLv2+CE	linux-arm64 linux-x64 macos-arm64 macos-x64 windows-arm64 windows-x64
Oracle	Oracle JDK 21	Oracle No-Fee	linux-arm64 linux-x64 macos-arm64 macos-x64 windows-x64
Red Hat	Red Hat build of OpenJDK 21	GPLv2+CE	linux-x64 windows-x64
SAP	SapMachine 21	GPLv2+CE	aix-ppc64 alpine-x64 linux-arm64 linux-ppc64le linux-x64 macos-arm64 macos-x64 windows-x64

Data Source

Sandbox

Instantly compile and run Java 21 snippets without a local Java installation.

import java.lang.reflect.ClassFileFormatVersion; public class Java21 { public static void main(String[] args) { var v = ClassFileFormatVersion.latest(); System.out.printf("Hello Java bytecode version %s!", v.major()); } }