Minecraft 26.x vs 1.21.11: which version should your server run?

The short version

Which server software supports which version (live)

✓ = MCJarHub has a build for that Minecraft version; "exp." = only experimental (alpha/beta) builds so far; — = none yet.

Built from the upstream data MCJarHub syncs every hour, so it changes as projects release updates. For a new release in progress, see the latest versions page.

Stay on 1.21.11 if…

• a plugin, mod or modpack you rely on has no 26.x build yet — check each one before upgrading, the table above only covers the server software itself;
• you cannot install Java 25 on your host yet (1.21.11 runs on Java 21);
• your players' clients or launchers are still on 1.21.11 and you don't run a protocol plugin.

Move to 26.x if…

• your server software has stable builds for it (not only experimental ones) — for Paper, wait for a stable build before switching a live world;
• your plugins/mods have been updated;
• you want the current game version that new players' launchers default to.

How to upgrade safely

1. Make a full backup of the server folder — a world opened on 26.x cannot be taken back to 1.21.11.
2. Install Java 25 and point your start script at it (UnsupportedClassVersionError means the wrong Java is still used).
3. Download the new build of the same software (e.g. Paper 26.3 or vanilla 26.3), swap the jar and update plugins/mods at the same time.
4. Test on a copy of the world first if you can.

Searching for "Minecraft 1.26"? That numbering does not exist: Mojang went from 1.21.11 to 26.1. MCJarHub redirects addresses like /jar/paper/1.26.2 to the matching 26.x page.