Tutorials/Update Java

Updating Java is important to do as a Minecraft player, as some technical bugs may be fixed only by updating Java.

'''The Minecraft launcher is bundled with Java version 1.8.0_51 (Java version 1.8.0_74 on macOS), which is used by default. Minecraft snapshot 21w19a to 1.18 Pre-release 1 comes with Java 16.0.1. Minecraft snapshot 1.18 Pre-release 2 or newer comes with Java 17.0.1.''' It is possible to change the used Java version in the profile options menu.

What is Java?
Java is a programming language and computing platform. Unlike many other languages, Java does not run directly on the hardware, but in a virtual machine, called the JVM (Java Virtual Machine). Minecraft is written in Java, and uses it for game logic, rendering, and networking.

As of November 16, 2021, the latest stable Java versions are 1.8.0_311 (Oracle JDK) / 1.8.0_312 (OpenJDK) (Long-Term Support or LTS), 11.0.13 (LTS) and 17.0.1 (LTS), while the latest development build is version 18 early-access build 23. Currently, you cannot use Java 17 or 18 EA with 1.17 and 1.17.1.

Why update?
The latest versions of Java contain important enhancements to help improve performance, stability and security of the Java applications that run on your machine. Installing the latest Java update ensures that Minecraft continues to run safely and efficiently.
 * Different Minecraft versions have different requirements of minimum Java version.
 * From Java Edition 1.12(17w13a) to Java Edition 1.16.5(1.17: 21w18a), Minecraft requires Java 8 (1.8.0) or newer.
 * From Java Edition 1.17(21w19a) to Java Edition 1.17.1(1.18: 1.18 Pre-release 1), Minecraft requires Java 16 or newer.
 * Since Java Edition 1.18(1.18 Pre-release 2), Minecraft requires Java 17 or newer.
 * Minecraft may sometimes crash without being run by a relatively modern version of Java.
 * Java updates fix lots of problems and bugs and typically cause increases in performance.
 * For example, the newer garbage collectors can help with lag spikes during high memory usage.
 * Running a server requires your computer to have Java installed instead of the pre-installed Java. See Tutorials/Setting up a server for more information.

Where to download
You can get Java either from Oracle or from someone who builds OpenJDK. For the purpose of Minecraft they are essentially the same, but Oracle's "OTN" version requires a PAID license for commercial and production purposes. If you make money from streaming Minecraft or running a Minecraft server (even non-profit), you MUST use OpenJDK unless you want to figure out how to pay.


 * Adoptium OpenJDK (Continuation of AdoptOpenJDK)(stable builds only, check github.com/adoptium for development builds)
 * AdoptOpenJDK (stable and development builds)(From July 2021 no new jdks will be produced. All production of further builds has been moved to adoptium.net)
 * Zulu OpenJDK (recommended) (stable and development builds)
 * Oracle OpenJDK (stable and development builds) – zip packages only (no installer)
 * Oracle JRE (NOT recommended instead you pay) (stable "OTN" builds)

You will see that Java is divided into LTS (long-term support) like 11 and STS (short-term support) version numbers like 16. An LTS version will be given updates for longer, so people tend to use them as a stable standard of "modern, but not too new" Java.

Other VMs
With sources like AdoptOpenJDK you might see a choice between HotSpot VM and something else. The VM is what actually executes the Java code, and HotSpot is the one written by Oracle and used in "official" releases. Some other VMs include:
 * IBM's OpenJ9, optimized for low memory and fast startup
 * Oracle's GraalVM, also optimized for low memory and fast startup; basically HotSpot on steroids

GraalVM is usually included in HotSpot in the form of "JVMCI" in JDKs 10 - 16. OpenJ9 takes a separate download.

How to update
When you install Java, go to your launcher, edit or create an installation, and in the Java Executable box, type  (Windows) or:  (Linux) or:   (macOS). The exact value depends on where your java is installed.

You must remove  from your JVM Arguments. This option is meaningless for Java 9 and newer, and will cause a launch failure if you keep it there.

Known issues

 * In Java 11 or newer, a very rare crash may occur in world generation code . A fabric mod called Voyager exists to fix this issue. If you are using fabric API 0.26.2 or above, this mod is not needed as the fix is included.This bug was fixed in 1.17 snapshot 21w20a and hence does not exist from 1.17+.
 * Do not upgrade if you are using Intel HD2xxx/3xxx graphics on Windows 10, as the driver is bugged. Java 8 uses a slower rendering method that makes it work, and that is mainly why Mojang stuck to this old version. Funnily enough, the current minimum GPU requirement for Minecraft appears to be Intel HD4xxx graphics, which would make this fix from Mojang seem obsolete as Java 8u211 could potentially offer more stability if they implemented it.