What Java Version for Minecraft? The Full Table, Version by Version

Every row below comes from the javaVersion field in Mojang's version JSON files, which the launcher reads before it starts the game. The component column is the name of the runtime package the official launcher downloads; it is useful when you are reading launcher logs or looking inside the launcher's runtime folder.

Use the one your Minecraft version needs. For 26.1, 26.2 and 26.3, that is Java 25, and Java 21 will not work: the game's code is compiled for Java 25, so a Java 21 runtime refuses to load it. Mojang's 26.1 changelog states it plainly: the game now requires Java 25, and the launcher now ships the Microsoft build of OpenJDK 25.

For 1.20.5 through 1.21.11, including 1.21.1, Mojang's metadata names Java 21, and that is what the official launcher gives those versions. If you run your own launcher or server for 1.21.x, install Java 21 and point that instance at it.

A newer Java can run code compiled for an older one, which is why some players run 1.21.x on Java 25 without trouble. It is not what Mojang ships for those versions, and older loaders and mods are the usual casualty when a Java runtime is newer than the one they were built and tested against. When a modded 1.21.x instance misbehaves on Java 25, moving it back to Java 21 is the first thing to try.

As for performance, we have no benchmark to cite comparing the two, so we will not claim one is faster. The version requirement decides it anyway.

No. Adoptium's release API listed Java 26 and 27 as available feature releases on 21 October 2026, with Java 25 as the most recent long-term support release. Long-term support versions are the ones distributors keep patching for years; the versions in between are supported for a much shorter time.

Minecraft has only ever required long-term support releases: 8, 17, 21 and now 25, with Java 16 for 1.17 as the one exception in the table. For Minecraft, install Java 25 for 26.x and do not go looking for a newer one. Nothing in Minecraft asks for Java 26 or 27.

If you play through the official Minecraft Launcher, including modded profiles that the Fabric or Forge installer created, you normally never install Java at all. The launcher reads the version's javaVersion field, downloads that runtime component, and uses it for that profile only. Your 1.20.1 Forge profile runs on Java 17 and your 26.3 Fabric profile on Java 25, side by side.

The one way to break this is a custom Java path. In the launcher's Installations tab, edit the profile and open More Options. If the Java executable field points to a specific java.exe or java binary, the launcher uses that instead of the bundled runtime, even when it is the wrong version. Older guides sometimes told people to set this. Clear it and the launcher goes back to choosing correctly.

26.1 also changed the launcher's default memory and garbage collector: Mojang's changelog says the game now allocates 4 GB by default instead of 2 GB and uses ZGC on compatible devices, and warns that third-party launchers may not support these changes.

Third-party launchers use whatever Java you give them, per instance. Prism Launcher's documentation says that from version 9.0 it can handle this automatically on Windows, macOS and Linux: turn on 'Autodetect Java version' and 'Auto-download Mojang Java' in Settings, Java, and it downloads the right runtime for each Minecraft version. The same page notes that the downloader is missing from most Linux packages other than the official Flatpak and AppImage.

If you prefer to manage Java yourself, install the versions you need, then in Prism open the instance's Edit, Settings, Java page and use Auto-Detect to pick the matching one. Do this per instance, because a 1.20.1 pack and a 26.3 pack need different runtimes.

The Fabric installer jar and the Forge and NeoForge installer jars also need a Java runtime to start, since they are Java programs themselves. Fabric's documentation puts it this way: the Minecraft Launcher comes with its own Java, so installing Java yourself is only needed for the Fabric .jar installer or the server .jar, and for 26.1 or newer that means at least Java 25.

Use an OpenJDK build from a reputable vendor. Fabric's documentation sends you to Adoptium, Prism's lists it among the vendors it recommends, and Adoptium's long-term support releases on 21 October 2026 were 8, 11, 17, 21 and 25. Prism's documentation recommends against Oracle's consumer Java because of its licensing and account requirements.

On Windows, download the x64 .msi for the version you need. Fabric's guide says to set two installer features to 'Entire feature will be installed on local hard drive': 'Set JAVA_HOME environment variable', which also adds Java to your PATH, and 'JavaSoft (Oracle) registry keys'. Restart afterwards, because Windows does not always tell other programs about the new Java until you do.

On macOS, take the .pkg for your chip: aarch64 for Apple silicon, x64 for Intel. On Linux, use your distribution's packages or Adoptium's repository. Then confirm in a terminal.

Different Java versions do not conflict. Install 17, 21 and 25 together if you play 1.20.1, 1.21.1 and 26.3, and leave them all in place. What you must control is which one each program uses.

The PATH decides which java a terminal command or a double-clicked installer finds, and only one can be first. Launchers and servers should not rely on it: select the runtime per instance in Prism, and give servers the full path to the java binary in their start script.

To see what you have installed: on Windows, run 'where java' in Command Prompt; on macOS, run '/usr/libexec/java_home -V'; on Linux, look in /usr/lib/jvm or use your distribution's alternatives tool.

This error means a piece of code was compiled for a newer Java than the one running it. It names two class file versions: the one the code needs, and the highest the running Java understands. The Java SE 25 edition of the JVM Specification lists major versions 45 through 69 as the ones a Java 25 runtime supports, and each Java release adds one, so the class file major version minus 44 is the Java version.

Read the first number to find what is needed, and the second to find what you are running. 'Class file version 69.0, this version recognizes up to 65.0' means the code needs Java 25 and you are on Java 21: you are launching a 26.x game, loader or mod with the 1.21-era runtime.

The fix is always the runtime, never the mod. Point that instance, installer or server at the Java version from the table, or clear the custom Java path on the official launcher, and relaunch. The checker above decodes the number for you if you paste it.

Knowing what Java version for Minecraft is required only helps if the game is actually using it, and java -version tells you about your terminal, not about Minecraft. To see what the game ran on, open the crash report or the latest.log for that instance. Crash reports end with a System Details section that includes a Java Version line and the path of the runtime, which is the authoritative answer.

In Prism, the instance's log window prints the Java path and version at the top of every launch. On a server, the first lines of the console output and logs/latest.log do the same.

If the version shown there does not match the table, you have found your problem. Our crash report guide walks through the rest of a report once the Java line checks out.

A dedicated server has no launcher choosing a runtime for it. It runs on whatever java its start command finds, which on a machine that has had Java installed for something else is often the wrong one. The answer to what Java version for Minecraft servers need is the same table: a 26.3 server, vanilla or modded, needs Java 25; a 1.20.1 Forge server needs Java 17.

Call the runtime by its full path in the start script so a system update cannot change it underneath you. On a rented server, use the host's Java version selector in its control panel instead, and set it to match the pack rather than leaving the default.

The 26.1 changelog's new 4 GB default and ZGC apply to the official launcher's client profiles. A server uses the -Xmx value and flags in your start command, so set memory there.

Most modded players are not on 26.3. On 21 October 2026, Modrinth listed 25,280 Forge mods for 1.20.1 and 21,514 NeoForge mods for 1.21.1, against 8,116 Fabric mods for 26.3, so going back a version is often the right move for a big pack. In the official launcher, open Installations, choose New installation, pick the version from the list, give it a clear name such as '1.20.1 Forge', and set its own Game directory so its mods, configs and saves stay separate. The launcher fetches the matching Java the first time you play it.

Worlds only move forward. Opening a world in a newer version upgrades it, and an upgraded world should never be opened in an older version again. 26.1 made this stricter: Mojang's changelog says it changed how worlds are stored on disk, moving each dimension into a dimensions folder and player data into a players folder, and worlds that need converting show an Upgrade and Play button. Copy the world's folder somewhere outside the game directory before any version change, and treat a downgraded installation as needing its own worlds.

Adoptium and other vendors offer a JRE, which is just the runtime, and a JDK, which adds development tools such as the compiler. Either one runs the game, the loader installers and a server.

Take the JDK if you are unsure. Some tools expect utilities that only ship with it, and you will need it anyway if you ever build a mod yourself. The only cost is disk space.